Evgenii Lifshitz, On the gravitational stability of the expanding Universe.

Journal of Physics (USSR) 10 no 2, pp. 116 – 129 (1946).

This was the first and fundamental paper on perturbations in cosmology. It is accompanied by an editorial note article by G.F.R. Ellis which describes the subsequent development of the field. Both articles are part of the Golden Oldies series in the

journal “General Relativity and Gravitation”. The two are in volume 49, numbers 17 and 18 (2017) and can be accessed on the journal’s website.

A full list of the previous Golden Oldies can be found at webwork.uct.ac.za/~cwh/goldies.html as well as on the Living Reviews in Relativity site.

Malcolm MacCallum

Golden Oldies editor, “General Relativity and Gravitation”

Loop Quantum Gravity

The First 30 Years

Edited by: Abhay Ashtekar (Pennsylvania State University, USA),

Jorge Pullin (Louisiana State University, USA)

This volume presents a snapshot of the state-of-the-art in loop quantum gravity from the perspective of younger leading researchers. It takes the reader from the basics to recent advances, thereby bridging an important gap.

The aim is two-fold — to provide a contemporary introduction to the entire field for students and post-docs, and to present an overview of the current status for more senior researchers. The contributions include the latest developments that are not discussed in existing books, particularly recent advances in quantum dynamics both in the Hamiltonian and sum over histories approaches; and applications to cosmology of the early universe and to the quantum aspects of black holes.

Contents:

Introduction:

An Overview (Abhay Ashtekar and Jorge Pullin)

Foundations of Loop Quantum Gravity:

Quantum Geometry (Kristina Giesel)

Quantum Dynamics (Alok Laddha and Madhavan Varadarajan)

Spinfoam Gravity (Eugenio Bianchi)

Group Field Theory and Loop Quantum Gravity (Daniele Oriti)

The Continuum Limit of Loop Quantum Gravity: A Framework for Solving the Theory (Bianca Dittrich)

Applications of Loop Quantum Gravity:

Loop Quantum Cosmology (Ivan Agullo and Parampreet Singh)

Quantum Geometry and Black Holes (J Fernando Barbero G and Alejandro Perez)

Loop Quantum Gravity and Observations (Aurelien Barrau and Julien Grain)

20% Discount until August 31st 2017 using code WSSLPS20 at http://www.lqg30.com

]]>After studying Great Books at St. John’s College in Santa Fe, Aron Wall continued his studies in theoretical physis with Ted Jacobson at the University of Maryland, where he received his PhD in 2011. His thesis, a proof that black holes obey the second law of thermodynamics when coupled to quantum fields, was awarded the 2013 Bergmann-Wheeler Thesis Prize from the International Society on General Relativity and Gravitation. As a Simons Postdoctoral Fellow at the University of California, Santa Barbara, Wall broadened his research efforts toward the holographic principle, and showed, most notably, that the holographic entanglement entropy satisfies a quantum information inequality known as “Strong Subadditivity”.

In 2014, Wall became a Member of the Institute for Advanced Study (Princeton), where he was able to resolve some long-standing conceptional problems concerning black hole entropy. He constructed an increasing entropy formula for all possible higher curvature modifications to Einstein gravity. With William Donnelly, he gave a statistical-mechanical explanation for a puzzling effect whereby electromagnetic fields seemingly contribute negatively to the entropy of a black hole. He also spearheaded a new research program on a conjectured lower bound on the quantum stress-energy tensor, and proved the conjecture for a broad class of theories. These results have potential applications in high-energy and condensed-matter physics.

In August 2017, Wall expects to join the Stanford Institute for Theoretical Physics for a third postdoctoral position. He explains physics and theology in his personal blog: Undivided Looking.

Eric Poisson, President

International Society on General Relativity and Gravitation

With a colleague, I’m serving as a guest editor for a special issue of the IEEE / AIP journal “Computing in Science & Engineering”. The special issue is titled ”Supercomputing-Enabled Advances in Science & Engineering” and we’re interested in papers that report on impactful advances enabled by large-scale computing in any area of science / engineering. All submitted papers will be peer-reviewed.

Given the major discovery in our field over the past year that was possible (partly) thanks to large-scale computations of compact binary systems, we would love to see papers on that subject in this special issue. The submission deadline is November 1, 2017. You can find out more about the special issue here:

https://www.computer.org/cise/2017/03/01/supercomputing-enabled-advances-in-science-engineering-call-for-papers/

Please note that the papers should be written for a somewhat broader audience in mind (the readership of the journal spans all areas of computational science / engineering).

Thanks for your consideration.

Gaurav Khanna

“The Kerr/CFT correspondence and its extensions” by Geoffrey Compere (http://dx.doi.org/10.1007/s41114-017-0003-2) and “Interferometer techniques for gravitational-wave detection” by Charlotte Bond, Daniel Brown, Andreas Freise and Kenneth A. Strain (http://dx.doi.org/10.1007/s41114-016-0002-8).

Due to a technical error, the latter was published with a wrong article citation ID, which will be corrected as soon as possible. We would also like to apologize to the authors for the tremendous delays caused by workflow adjustments after the journal transfer to Springer.

]]>Vishveshwara was born on March 6, 1938 in Bangalore. He had his schooling there and then went on to Mysore University for further studies. He obtained the B.Sc.(Hons) degree in 1958 and the M.Sc. Degree from Central College of the then Mysore university in 1959. He then went to USA for higher studies. After getting his A.M. from Columbia University, New York, in 1964 he moved to University of Maryland from where he got his Ph.D. in 1968. His thesis advisor was Prof. C.W. Misner, the M of the directory of the universe, MTW. His thesis subject was “Stability of Schwarzschild Metric”. After stints as a post doctoral fellow and a visiting faculty member, at Institute of Space Studies (1968-69), Boston University (1969-72) , New York University (1972-74), University of Pittsburgh (1974-76), Vishu returned to Bangalore in 1976 and joined the Raman Research Institute. He moved from there, in December 1992, to the Indian Institute of Astrophysics, Bangalore as a Senior Professor, from where he retired in 2005.

One of the most important and bizarre predictions of General Relativity is the existence of black holes – objects from which nothing can come out including light. It marks a one-way surface which can only be crossed one way but not the other – things can fall in but nothing can come out. A brief historical aside is not out of place to give a flavour of the times when Vishu’s important papers were written.

Relativity revolutionized our understanding of space and time by first uniting them into a flat four dimensional space-time in special relativity and subsequently for describing gravity making it curved and dynamic in General Relativity. Gravity is no longer an external force but synonymous with the geometry of space-time. In 1915, Einstein finally arrived at the correct field equations completing the quest he began in 1907 to obtain General Relativity, his relativistic theory of gravitation. Mathematically the equations were complicated and so he was surprised that within a year Karl Schwarzscild discovered an exact solution of these equations representing a spherically symmetric, asympotically flat, vacuum solution, whose outer region is strictly static. The solution had an unusual feature that a certain component of the metric vanished while another diverged at what was referred to as the Schwarzschild singularity or better the Schwarzschild surface. Though in 1939 Oppenheimer and Snyder showed that a person who rides through this surface on an imploding star will feel no infinite gravity or see no breakdown of physics there, these results were not taken seriously due to the mental connotation associated with the word `singularity’ and due to the simple dust model used in the treatment. These objects were referred to as frozen star in Soviet union and collapsed star in the west. The realization that this was due to a choice of coordinates or a coordinate singularity was long time coming and conclusively settled in 1958 by Finkelstein (and later in 1960 by Kruskal) who discovered a new reference frame for the Schwarzschild geometry. In December 1967 , in his lecture on “Our universe, the known and unknown”, John Wheeler christened these objects as Black Holes, an idea that intrigues and fascinates the scientists and the lay public even to this day.

General Relativity is a complex mathematical theory and often involves subtleties in its physical interpretation related to the choice of coordinates used in its formulation. Can one use a description using more well-behaved coordinates? Even if mathematically a black hole solution exists, the possibility of it being a physical object in nature depends on whether it is stable. If the black hole is an object from which no information can escape, how can one look for it? Can one provide a mathematically elegant description of the physical effects of a rotating black hole like gyroscopic precesion? Vishu’s seminal research center on these topics and earned him the fond title of Black Holy man of India!

Among Vishu’s classics on this topic is a brief elegant paper using Killing vectors to provide a coordinate invariant distinction between the stationary Kerr and static Schwarzschild black hole cases and the consequent existence of the ergosphere [1]. Regarding this work Jacob Bekenstein commented [2]: “I was familiar with the Vishu theorem that the infinite redshift surface of a static black is always the horizon. At that time black hole physics was just getting started and such neat relations between black hole features were rare. Vishu’s theorem was a welcome hard fact in the middle of such folklore and helped clarify in mind what black holes were about. At the conference (GR6) I had a long talk with him and I vividly remember being impressed by the range of research problems he had going simultaneously.”

Vishu was the first to prove the stability of non-rotating black holes under linear perturbations [3]. Regarding this Brandon Carter remarked [2]: “Vishu was one of the first to appreciate the importance of this problem and who played an important role in persuading others to take the problem seriously as something of potential astrophysical relevance by providing the first convincing proof that at least in one case namely the Schwarzschild solution, such an equilibrium state can be stable.” Elaborating further Bernard Whiting wrote [2]: “Vishveshwara’s original discussion of stability showed that there was no superficial case establishing the instability basically by dealing with single modes and by demonstrating the positivity of effective potentials. Establishing pointwise boundedness requires use of more refined tools leading to a method that differs markedly in substance but not at all in essence from the relatively simple positive potential approach. Vishu made a number of significant breakthroughs…”:

Vishu was the pioneer who explored how black holes respond when externally perturbed [4] and proved that regardless of the perturbation, Schwarzschild black holes get rid of any deformation imparted to them by radiating gravitational waves with a frequency and decay time that depended only on their mass. These characteristic waves are technically termed quasi-normal modes, which is why after the announcement of the gravitational wave detection by LIGO Vishu laid the claim to the non de plume “Quasimodo of black holes”. Quasi-normal modes are like the dying tones of a bell struck with a hammer and are referred to as the ringdown radiation. Vishu’s work is fundamental to our understanding of black holes and began a new chapter in how to study them.

Many of us met Vishu during the Einstein Centenary symposium at Physical Research Laboratory, Ahmedabad in 1979. Though we have other wonderful memories of the symposium the most memorable one was Vishu’s lecture entitled ‘Black Holes for Bedtime’. It was a magical experience; an exotic cocktail of science, art, humour and caricature. Equations were not necessarily abstract and unspeakable and could well be translated in the best literary tradition if you were Vishu!

At Raman Research Institute and later Indian Institute of Astrophysics Vishu explored problems in classical general relativity with possible astrophysical implications. Perturbations of black holes in general relativity carry signatures of the effective potential around them and one could look for them by examining neutrinos in gravitational collapse or ultracompact objects. Could one discern possible differences between black hole solutions in general relativity and other theories of gravity by looking at their quasi-normal modes and the properties of their horizons. How different are black hole solutions in cosmological backgrounds from those in the usual asymptotically flat ones. How does one use the Frenet-Serret formalism to study gyroscopic precession, general relativity analogs of inertial forces and characterize black holes in higher dimensions in a covariant and geometric manner. Other mathematical issues studied related to separability of different spin perturbations in general relativity, the role of the Killing tensor in separability of wave equations among others. It was always a pleasure working with Vishu. There was no pressure, no generation gap, a natural possibility to grow and contribute your best, an easy personal rapport, a refreshing sense of humour, an unassuming erudition and most importantly a warm and wonderful human being.

Together with J.V. Narlikar, Vishu played a key role in bringing long due recognition to the doyens of general relativity P.C. Vaidya and A.K. Raychauduri. A volume entitled ‘Random walk in relativity and cosmology’ co-edited by them was released in 1986 at RRI and the royalities from its royalties supplemented by royalties of the International Conference on Gravitation and Cosmology (ICGC) proceedings used to set up the Vaidya-Raychaudhuri endowment lecture of the Indian Association for General Relativity and Gravitation (IAGRG). Vishu was closely involved in the group that initiated, planned and organized UGC Schools on general relativity and cosmology in the 1980’s. The motivation was to extend Indian research in exact solutions in general relativity to modern research frontiers in cosmology, early universe and relativistic astrophysics. This led to the ICGC meetings organized every four years because it was recognized that due to limited resources, participation of the Indian researchers in the International Society of General Relativity and Gravitation (ISGRG) meetings was very limited. Creating an opportunity to for the IAGRG community to interact with international experts on front line research areas in relativity and cosmology in India was needed to assist in improving the quality and relevance of general relativity research in India. These meetings also brought out the cartoonist in Vishu during the first ICGC in Goa. Between sessions cartoons would appear on the screen anonymously and by the end of the meeting multiple reprint requests for them! Staid Cambridge University Press was happy to include them in the proceedings and Vishu’s cartoons in the ICGC proceedings a treat to look forward to. The series of cartoons on gravitational waves in those proceedings deserves special mention.. Alas they are incomplete since he could not make one after the discovery.. Just on the day he passed away Nils Andersson wrote Vishu an email: “I have recently done something that I think might amuse you. I have written a little book involving Einstein, relativity and a fair bit of fictional freedom. Now, I think it is fair to say that my attitude to this project has been heavily inspired by your story-telling, your drawings and the bathtub book [5].”

Vishu’s public lectures inspired a number of students all over the country. His lectures at Bangalore Science Forum, started by his Guru Dr H. Narsimiah, always drew huge numbers. He was a best-seller. And, he never disappointed the audience. Without diluting the profound ideas that he would discuss, he would lace the talks with subtle humour that came seamlessly. At Vishu’s passing, countless echoed Sathyaprakash who exclaimed “This is devastating. I have lost a teacher, a mentor and a friend. More than anything else we are going to miss his “serious” sense of humour in all walks of life, especially science.”

Together with a committed group that included Sanjay Biswas, Vishu was involved in bringing out Bulletin Of Sciences from 1983-1993 to set up a forum to seriously address the social impact of science and technology. To find means of sustaining it financially he co-edited with Sanjay Biswas and D.C.V Mallik an interesting volume called Cosmic Perspectives that was dedicated to the memory of M. Vainu Bappu. Together with A. Ratnakar Vishu was instrumental in setting up the RRI Film Club in the 1980’s to get access to movie classics from National Film Archives in Pune and from the consulates like the German and French ones.

Jawaharlal Nehru Planetarium (JNP), Bangalore is a wonderful testament to Vishu’s vision which showcases his multi-faceted personality in science communication and education. Starting as its founder director in 1988, Vishu brought together a dedicated and talented team and inspired them to build a world class planetarium scripting unique shows integrating the best in science and astronomy with the best in world and Indian history, art, literature and music. By example he set up high standards for all the JNP personnel and mentored them till the very end. But JNP was not to be just a theatre. It had to play a role in science education in the city. Thus in 1992 Bangalore Association for Science Education (BASE) was set up by Vishu to systematically expose, attract and mentor students from school, high school and colleges for a career in science. It may surprise many that in spite of being a pure theorist, Vishu firmly believed in doing science experiments. Via activities like `Science in Action’ he emphasized the importance of bringing out in young students the joy of seeing scientific phenomena. That was a way to attract them to science. In fact this philosophy of ‘doing’ science underlined every activity that was visualized at JNP in the coming years. SEED (Science Education in Early Development) for middle school children, SOW (Science Over the Weekends) for high school children and at the pinnacle of the educational programmes, REAP (Research Education Advancement Programme) for undergraduate students. SEED, SOW and REAP, all have a very strong presence of experiments that make the programmes dynamic and vibrant and endearing to students. During the last twenty years, all these programmes have seen a steady growth in number of students attending them and also in attracting quality students with a potential to excel in a career in science. No wonder that more than hundred students who passed through JNP are either pursuing PhD programmes or have completed it. Some of them are faculty at institutions such as ICTS, JNCASR and IMSc. Finally, setting up of a science park at JNP was also his initiative. In the original plan drawn up in 1997, Antigravity Cottage that mimics the famous ‘Mystery Spot’ in the US and some other places had been envisaged. It was realised in 2016.

When the gravitational wave discovery by LIGO was announced last year, Vishu was elated. We have never seen him so high, thrilled by the possibility that soon there would be events where the quasi-normal modes would be even more strong. The profoundness of this discovery is in the realization that the black hole, which is purely a geometric object without any hard surface boundary rings under perturbations like a material object. It is indeed the most telling and ‘visible’ defining property of a black hole. And Vishu was its discoverer. By all accounts, it is a discovery that will go down to textbooks. If that be the benchmark, there are only a few other contributions from India like the Raychaudhuri equation and Vaidya’s radiating star that will make the grade. On the other hand this discovery sits alongside the celebrated result that a black hole has no hair -the ‘No Hair’ theorem. Most important of all, it is one of the few predictions that have been brilliantly verified by the observation of gravitational waves produced by merger of two black holes. The observed profile has very uncanny resemblance with what Vishu had plotted long back in 1970. There are very few predictions which are actually verified by experiment and observation. Vishu’s black hole ringdown is one among those few. This is the true and ultimate measure of a seminal insight.

We will miss you Vishu even as we try very hard to follow your favorite lines from Machado: Traveller there is no Path, Paths are made by Walking ..

Vishu is survived by his wife Saraswati and two daughters Smitha and Namitha.

Naresh Dadhich, IUCAA

Bala Iyer, ICTS-TIFR

[1] Generalization of the “Schwarzschild Surface” to Arbitrary Static and Stationary Metrics, C. V. Vishveshwara, J Math. Phys., 9, 1319 (1968).

[2] Black Holes, Gravitational Waves and the Universe, Essays in honor of C.V. Vishveshwara, Eds. B. R. Iyer and B. Bhawal, Kluwer, (1999).

[3] Stability of the Schwarzschild Metric, C. V. Vishveshwara, Phys. Rev. D, 1, 2870 (1970),

[4] Scattering of Gravitational Radiation by a Schwarzschild BlackHole, C. V. Vishveshwara, Nature, 227, 936 (1970)

[5] Einstein’s Enigma or Black Holes in My Bubble Bath, C.V. Vishveshwara, Springer-Verlag, Berlin-Heidelberg (2006).

Naresh Dadhich

Inter-University Center for Astronomyand Astrophysics,

Pune 411 007, India

Bala Iyer

International Centre for Theoretical Sciences – TIFR,

Bengaluru 560 089, India

e-mail: bala.iyer[AT]icts.res.in

Reproduced with permission from CURRENT SCIENCE (Vol. No. 112, 25 February 2017, pp. 866-868).

]]>Hypersurfaces can be defined and the extrinsic curvature and constraint equations can be evaluated. Support is provided for timelike, spacelike and null hypersurfaces in a four dimensional spacetime.

Junctions of two spacetime manifolds by the identification of a common hypersurface can be performed and the Darmois-Israel junction conditions can be calculated (for null hypersurfaces, the Barrabes-Israel conditions). The stress-energy of any resulting shell and equations for shell evolution can be determined.

A number of example worksheets are provided. In most cases they follow the examples provided in “A Relativist’s Toolkit” by Eric Poisson.

This update brings the features formerly found in the GRJunction package directly into GRTensorIII.

GRTensorIII is available on github at: https://github.com/grtensor/grtensor

GRTensorIII requires Maple (http://www.maplesoft.com/)

The hypersurface and junction documentation can be viewed at:

https://github.com/grtensor/grtensor/blob/master/doc/grHyper.pdf

Peter Musgrave

]]>SageManifolds is devoted to explicit tensor calculus (as opposed to “abstract tensor calculus”): the dimension of the manifold must be specified and some atlas must be provided. SageManifolds 1.0 functionalities include

– topological manifolds: charts, open subsets, maps between manifolds, scalar fields

– differentiable manifolds: tangent spaces, vector frames, tensor fields, curves, pullback and pushforward operators

– standard tensor calculus (tensor product, contraction, symmetrization, etc.), even on non-parallelizable manifolds

– taking into account any monoterm tensor symmetry

– exterior calculus (wedge product, exterior derivative, Hodge duality)

– Lie derivatives of tensor fields

– affine connections (curvature, torsion)

– pseudo-Riemannian metrics

– some plotting capabilities (charts, points, curves, vector fields)

Example of use, in particular in the context of general relativity, are posted at

http://sagemanifolds.obspm.fr/examples.html

Visit http://sagemanifolds.obspm.fr/ for free download and run.

Eric Gourgoulhon (on behalf of the SageManifolds team: http://sagemanifolds.obspm.fr/authors.html )

]]>Jorge V. Rocha is a theoretical physicist from Lisbon, Portugal, whose research interests revolve around gravitational theories and black holes. He completed his undergraduate studies with distinction at Instituto Superior Tecnico (IST) and obtained a PhD degree in Physics from University of California, Santa Barbara in 2008, under the supervision of Prof. Joseph Polchinski. He moved on to a first postdoctoral position with Prof. Vitor Cardoso in Centro Multidisciplinar de Astrofísica-IST. Since 2015, Jorge V. Rocha has been at Universitat de Barcelona with a Marie Sklodowska-Curie individual Fellowship, under supervision of Prof. Roberto Emparan.

]]>Nominations for the 2017 Bronstein Prize are invited. The nominee should hold a (non-faculty) post-doctoral position at the time of the nomination deadline. The primary criterion will be high quality of scientific results in loop quantum gravity, interpreted in the broadest sense, creativity and originality, and the significance of results to the field as a whole. The 2013 and 2015 winners of the prize were Drs. Eugenio Bianchi and Edward Wilson-Ewing, respectively

The nomination packet should consist of: i) A ~1 page nomination letter summarizing the specific achievements to date of the nominee; ii) A complete CV and a publication list of the nominee; iii) 2 letters of support from experts emphasizing the broad significance of all research contributions to date of the nominee; and, iv) A proposed citation. Self nominations will not be considered. The entire packet should be bundled into a single PDF file and e-mailed to Ms. Randi Neshteruk (rxh1[AT]psu.edu) by Tuesday, January 30th 2017.

The prize consisting of a certificate and a monetary reward will be presented during the Loops 2017 conference, which will be held at the University of Warsaw from July 3rd to 7th, 2017.

]]>The Gravitational Wave International Committee is pleased to announce that nominations for the 2016 GWIC Thesis Prize and for the 2016 Stefano Braccini Thesis Prize are now open. Both prizes recognize outstanding PhD theses in the general area of gravitational waves. To better serve the community, GWIC and the Friends of Stefano Braccini have moved to coordinate the two Prizes. There is a common call for nominations, and all theses submitted will be considered for both awards by a joint selection committee. Two winners will be selected, with the GWIC Thesis Prize emphasizing the impact of the research on the field of gravitational wave science, while the Braccini Thesis Prize will be awarded with an emphasis on innovation.

Members of the gravitational wave community are invited to nominate students who have performed notable research on any aspect of gravitational wave science. Theses will be judged on 1) originality and creativity of the research, 2) importance to the field of gravitational waves and gravitational wave detection, broadly interpreted, and 3) clarity of presentation. Each winner will receive a certificate of recognition and a prize of US$ 1,000.

GWIC is privileged to nominate both thesis prize winners for publication in the book series Springer Theses. Subject to certain qualifications, Springer Theses publishes exceptional Ph.D. theses in the physical sciences in their entirety. If accepted, each winner will receive an additional 500 Euros from Springer upon publication.

Eligibility: Both prizes are awarded on a calendar year basis. Theses should have been accepted by their institutions between 1 January 2016 and 31 December 2016. It is expected that many of the nominations will come from the member projects of GWIC, but this is not a requirement. Nominated theses may be in any language. A committee selected from the gravitational wave community will evaluate the nominations and select the winner. The selection committee will make all determinations about eligibility.

Nominations: Nominations should be submitted by 31 January 2017. The nomination package consists of (i) the thesis, (ii) a letter of nomination, preferably from the thesis advisor, and (iii) a supporting letter from another scientist familiar with the work. The nomination and supporting letters should describe the importance and novelty of the research and the student’s particular contribution.

Electronic submission of the thesis and letters is strongly preferred, with the thesis and the letters in separate pdf files. Electronic copies of the nomination materials may be sent to the Stan Whitcomb (stan[AT]ligo.caltech.edu). All submissions will be acknowledged; if an acknowledgement is not received shortly after the deadline, please contact the GWIC Secretary (gwic-exsec[AT]gravity.psu.edu).

If electronic submission is impossible, please contact the GWIC Secretary (gwic-exsec[AT]gravity.psu.edu) for instructions concerning paper submission.

]]>http://www.minkowskiinstitute.org/mip/books/ase-mtr.html

]]>With this open-access journal we hope to make the connection between the computational science and the astrophysics communities. In that respect I hope that you will enjoy reading these pioneering papers as much as I have enjoyed them. The following list of publications reflects only a small part of the range in scientific topics we seek for in this journal.

Recent articles:

– “Riemann solvers and Alfven waves in black hole magnetospheres” by B Punsly, D Balsara, J Kim and S Garain

– “In situ and in-transit analysis of cosmological simulations” by B Friesen, A Almgren, Z Lukic, G Weber, D Morozov, V Beckner and M Day

– “Achieving convergence in galaxy formation models by augmenting N-body merger trees” by A J Benson, C Cannella and S Cole

– “Simulations of stripped core-collapse supernovae in close binaries” by A Rimoldi, S Portegies Zwart and E M Rossi

If you are interested in submitting your own work to CompAC, you’ll find all the submission guidelines at the journal’s home page: http://comp-astrophys-cosmol.springeropen.com/

I look forward to reading your work.

Kind regards,

Simon Portegies Zwart

Editor-in-Chief

Computational Astrophysics and Cosmology

The CSE PhD program offers an excellent opportunity for students interested in an interdisciplinary program spanning applied mathematics, astrophysics, gravitational physics, large-scale simulation, and high-performance computing. Participating departments include Physics, Mathematics, Computer and Information Science, and Engineering. The CSE PhD program was created in 2011 and last year graduated its first class. We are committed to growing our PhD program with excellent students seeking an interdisciplinary, computationally-based research and educational experience.

Gravitational physics and computational astrophysics groups include faculty members Scott Field, Dana Fine, Robert Fisher, Jong-Ping Hsu, David Kagan, Gaurav Khanna, and Richard Price.

Funding is available on a competitive basis via university fellowships, research and teaching assistantships. Deadline for full consideration for Fall 2017 admission is February 15th. Interested students are encouraged to contact Gaurav Khanna (gkhanna[AT]umassd.edu) for more information.

To learn more about CSE faculty members, PhD students, and ongoing research projects please see:

http://cscvr.umassd.edu/

To learn more about the UMass Dartmouth gravity and astrophysics groups please see:

http://gravity.phy.umassd.edu/

https://sites.google.com/site/fishercompgroup/

To learn more about the CSE program please see:

http://www.umassd.edu/engineering/graduate/doctoraldegreeprograms/egrandappliedsciencephd/cseoption/

The following years Marcus Ansorg spent at the Institute of Theoretical Physics (Jena, Germany), at the Center for Gravitational Physics and Geometry at The Pennsylvania State University (USA), at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Potsdam, Germany), and at the Helmholtz Center (Munich, Germany). While still in Jena, he developed novel numerical methods for the solution of the Einstein field equations with applications to rotating neutron stars. Marcus Ansorg’s spectral methods involving clever coordinate transformations improved the achievable accuracy by several orders of magnitude over previous methods. A further highlight during these years was his work on initial data for black holes, resulting in one of the most used data sets of its kind in numerical general relativity.

In 2010, Marcus Ansorg returned to the Friedrich Schiller University in Jena as Professor of Theoretical Physics / Theory of Gravitation. He was an enthusiastic lecturer and advisor, and his love of science and his productivity in general relativity remained undiminished. In recent years he successfully applied his numerical methods also in quantum field theory and quantum gravity.

Marcus Ansorg died after a severe illness, which prematurely ended his remarkable life and career. We mourn with his family the loss of a wonderful person and will honor and cherish his memory.

Bernd Bruegmann and Reinhard Meinel

]]>– interactive entry of spacetime metrics (including basis and NP formats)

– large number of standard tensor definitions (curvature tensors, vector field expansion/shear, scalar invariants)

– a powerful mechanism to define new tensor objects (grdef) without programming

– commands to simplify and extract component values

GRTensorIII is provided as a standard Maple package. It has been tested with Maple 2015 and 2016.

GRTensorIII is an update of the package GRTensorII developed by Peter Musgrave, Denis Pollney and Kayll Lake in the 1990s. GRTensorII has continued to be used by relativists and this update brings the package in line with “modern” Maple versions and fixes some platform-specific issues on MacOS. Most of the original code has been retained, with changes to allow it be released as a Maple module in a single package.

Peter Musgrave would like to thank Maple Software for the donation of Maple licenses. Thanks also to Eric Poisson for beta testing.

Peter Musgrave

Denis Pollney

Kayll Lake

Support: grtensor3[AT]gmail.com

]]>(1) We will make these Awards on May 15, 2017 for the best well-written essays, 1500 words or fewer (excluding abstracts and excluding a small number of equations, diagrams, figures, references and tables), on the subject of gravitation, its theory, applications, or effects. Essay ideas should be self-contained and understandable – not dependent on reading other documents.

(2)

The First Award will be $4000.00

The Second Award will be 1250.00

The Third Award will be 1000.00

The Fourth Award will be 750.00

The Fifth Award will be 500.00

(3) Essay must be in English and e-mailed in a single PDF file before April 1, 2017. One essay only will be accepted from each author. Notify us within 24 hours if you do not receive an e-mail confirmation of your submission.

(4) Title page should include essay title; authorsﾕ names (specify corresponding author), e-mail and mailing addresses; submission date; an abstract of 125 words or fewer; and the statement: Essay written for the Gravity Research Foundation 2017 Awards for Essays on Gravitation. Pages should be numbered.

(5) The decision of the judges will be final and no reviews or comments will be provided.

(6) Please check the winnersﾕ announcement to be posted on our website: www.gravityresearchfoundation.org around May 15, 2017. We will also attempt to send all participants a general e-mail notification.

(7) The five award-winning essays will be published in a special issue of the International Journal of Modern Physics D (IJMPD). Authors of essays designated Honorable Mention will be invited to submit their essays to the IJMPD where these may undergo additional refereeing at editorial discretion for possible publication. Authors of all other essays are free and encouraged to publish their essays after May 15th.

Submission e-mail address: George M. Rideout, Jr., President, grideoutjr[AT]aol.com

Recent First Award Winners:

2016 – Stephen L. Adler, Institute for Advanced Study, Princeton, New Jersey

2015 – Gerard ﾕt Hooft, Utrecht University and Spinoza Institute, the Netherlands

2014 – Lawrence M. Krauss, Arizona State University and Frank Wilczek, Massachusetts Institute of Technology (MIT)

2013 – Baocheng Zhang, Qing-yu Cai, Ming-sheng Zhan, Chinese Academy of Sciences, Wuhan and Li You, Tsinghua University, Bejing, PR China

2012 – Claus Kiefer and Manuel Kraemer, University of Cologne, Koeln, Germany

2011 – Ivan Agullo, Penn State and Leonard Parker, University of Wisconsin-Milwaukee

2010 – Mark Van Raamsdonk, University of British Columbia, Vancouver

2009 – Alexander Burinskii, Russian Academy of Sciences, Russia

2008 – T. Padmanabhan, IUCAA, Pune, India

2007 – S. Carlip, University of California at Davis

2006 – Vijay Balasubramanian, University of Pennsylvania; Donald Marolf, University of California at Santa Barbara and Moshe Rozali, University of British Columbia

2005 – John Ellis, CERN; N. E. Mavromatos, Kingﾕs College London and D. V. Nanopoulos, Texas AandM University

2004 – Maulik Parikh, Columbia University, New York

2003 – Martin Bojowald, The Pennsylvania State University

2002 – Steven B. Giddings, University of California at Santa Barbara and Stanford University

Bishop, N.T. and Rezzolla, L.,

“Extraction of gravitational waves in numerical relativity”,

Living Rev Relativ (2016) 19: 2.

http://doi.org/10.1007/s41114-016-0001-9

ABSTRACT:

A numerical-relativity calculation yields in general a solution of the Einstein equations including also a radiative part, which is in practice computed in a region of finite extent. Since gravitational radiation is properly defined only at null infinity and in an appropriate coordinate system, the accurate estimation of the emitted gravitational waves represents an old and non-trivial problem in numerical relativity. A number of methods have been developed over the years to “extract” the radiative part of the solution from a numerical simulation and these include: quadrupole formulas, gauge-invariant metric perturbations, Weyl scalars, and characteristic extraction. We review and discuss each method, in terms of both its theoretical background as well as its implementation. Finally, we provide a brief comparison of the various methods in terms of their inherent advantages and disadvantages.

Diverse Toolset: To achieve your goals, you will choose to focus on applied inverse problems; biomedical mathematics; discrete mathematics; dynamical systems and fluid dynamics; or geometry, relativity, and gravitation.

]]>As an affiliated commission (AC2) of the International Union of Pure and Applied Physics (IUPAP), the International Society on General Relativity and Gravitation (ISGRG) offers an annual IUPAP Young Scientist Prize. The IUPAP Young Scientist Prizes recognize outstanding achievements of scientists at early stages of their career. Each prize consists of a certificate citing the contributions made by the recipient, a medal and 1000 euros.

The conditions for the prize are:

The IUPAP General Relativity and Gravitation Young Scientist Prize can be for work in any area of relativity and gravitation, theoretical or experimental.

On 1 February 2017, nominees must have a maximum of eight years of research experience (excluding career interruptions) following the Ph.D. (or equivalent) degree. They are expected to have displayed significant achievement and exceptional promise for future achievements in relativity and gravitation.

THE PRIMARY NOMINATOR MUST BE A MEMBER OF THE INTERNATIONAL SOCIETY ON GENERAL RELATIVITY AND GRAVITATION.

Nominations may be made by any member of ISGRG (other than the nominee) and should be accompanied by a CV, a proposed citation of 30-50 words summarizing the reason for the nomination, a list of publications and a description (about one page long) of the specific achievements of the nominee, who need not be an ISGRG member.

It is important that the selection committee has specific information that allows it to determine what the nominee has contributed and how this will impact the subject. Therefore it will be extremely helpful to the selection committee to receive at least two additional letters supporting the nomination that detail the expected significance of the contributions of the nominee.

It is also appropriate to submit additional materials such as published articles. In the case of co-authored or multi-authored publications, it is essential for nominators and supporters to discuss the nominee’s precise contributions, if known, in addition to the work’s overall significance.

The entire package should be bundled into a single PDF file and emailed to the Secretary of ISGRG, beverlyberger[AT]me.com, by 1 February 2017. The winner will be announced on 14 March 2017 and the award made shortly thereafter. The official presentation of the award will be made at the GR22 conference in 2019.

]]>We are writing to you about some news that you might be interested in with respect to LIGO and Virgo observing runs.

In the expectation of regular future gravitational wave detections, the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration are seeking the help of numerical relativity groups in validating and interpreting gravitational wave signals. The immediate goal is rapid production of simulations of binary black hole coalescences in response to future detections. Gravitational waveforms from these simulations will be used to quantify accuracy of analytical waveform models, and in studies of systematic biases in parameter estimation and tests of general relativity. The simulations may also provide visualizations of binary black holes for outreach purposes. For details please see: (https://dcc.ligo.org/LIGO-T1600380/public)

Participating groups will join the LIGO Scientific Collaboration or the Virgo collaboration following rules of each collaboration; for joining LSC as a member see (http://ligo.org/about/join.php) or email gabriela.gonzalez[AT]ligo.org; for signing a memorandum of understanding focused on this specific subject with Virgo (http://ww.virgo-gw.eu) e-mail fulvio.ricci[AT]roma1.infn.it. Joining groups will perform simulations, coordinated within the LVC working groups ‘Compact Binary Coalescence’ and ‘Burst’.

Given the rapid flux in the emerging field of gravitational wave astronomy, the scope of this announcement is limited to the second observing run, which is scheduled to run approximately from December 2016 to mid-2017. This call for membership is primarily targeting vacuum general relativity. If interested please contact the LIGO or Virgo spokespersons as soon as possible. Please feel free to share this information with your colleagues or recommend names of other groups that may be interested. Thanks in advance for your interest.

Gabriela Gonzalez (LIGO Scientific Collaboration spokesperson)

Fulvio Ricci (Virgo Collaboration spokesperson)

Dietrich was born on May 24, 1939 in Weida/Thuringia and discovered his interest in the sciences early on. He was a student at the University of Jena from 1957 to 1962 and earned his Diplom in Physics with honours. At that time, Prof. Schuetz held experimental physics, Prof. Eckardt Technical Physics, Prof. Schuster and Drs Schmutzer and Weber Theoretical Physics. In 1966, he received his doctorate with a dissertation entitled “Bispinor Fields in Curved Spaces” with Prof. Ernst Schmutzer as his supervisor, whom Dietrich Kramer held in high esteem throughout his life. He then turned his research attention to exact solutions of Einstein’s field equations, a field in which he received international acclaim. The year 1980 was marked by particular success, when he was awarded a prize from the Gravity Research Foundation for the article “Soliton Concept in General Relativity”, was invited to hold a plenary lecture at the GR9 conference, and Cambridge University Press published the monograph “Exact Solutions of Einstein’s Field Equations” that he had co-authored with Stephani, MacCallum and Herlt – still a highly cited standard work.

In 1970, Dietrich Kramer received his habilitation with a thesis on “Invariance Transformations of Exact Vacuum Solutions in General Relativity”, which marked the beginning of his long-standing teaching activities and duties at the Department of Physics in Jena. The long overdue professorship was given to him in 1992 after the German reunification. In the decade that followed, he continued his successful research and teaching career. In addition, he also took on administrative responsibilities such as Director of the Theoretical Physics Institute that was now open to scientists from both sides of the former iron curtain and attracted guests from around the world.

Prof. Dietrich Kramer passed away on August 30, 2016 after a protracted illness. He will be fondly remembered by all his colleagues and students as a deeply caring and dedicated person.

Gernot Neugebauer and Reinhard Meinel

]]>This book offers a systematic exposition of conformal methods and how they can be used to study the global properties of solutions to the equations of Einstein’s theory of gravity. It shows that combining these ideas with differential geometry can elucidate the existence and stability of the basic solutions of the theory. Introducing the differential geometric, spinorial and PDE background required to gain a deep understanding of conformal methods, this text provides an accessible account of key results in mathematical relativity over the last thirty years, including the stability of de Sitter and Minkowski spacetimes. For graduate students and researchers, this self-contained account includes useful visual models to help the reader grasp abstract concepts and a list of further reading, making this the perfect reference companion on the topic.

Length: 622 pages, contains 73 b/w illustrations.

ISBN: 9781107033894

Organisers:

NISSANKE, Samaya (chair)

FENDER, Rob

KULKARNI, Shri

OFEK, Eran

DAVIES, Melvyn

FYNBO, Johan

1. All presentations during the Chalonge – de Vega 20th Paris Cosmology Colloquium 2016 are available on line in pdf format in “Programme and Lecturers .pdf ” here:

http://chalonge.obspm.fr/Programme_Paris2016.html

http://chalonge.obspm.fr/colloque2016.html

Contents: Peter Biermann , Maria Cristina Falvella, Anastasia Fialkov, Gerard Gilmore, Mattew Greenhouse, Dmytro Iakubovskyi, Anthony Lasenby, Nicola Menci, Felix Mirabel, Sinziana Paduroiu, Paolo Salucci, Norma G. Sanchez, George F. Smoot, Benjamin Wandelt Casey Watson, Christian Weinheimer.

The Album of Pictures of the Colloquium is available here:

http://chalonge.obspm.fr/album2016/index.html

http://chalonge.obspm.fr/colloque2016.html

2. The Hector J. DE VEGA MEDAL was presented and awarded. A Summary of the medal presentations is available here:

http://chalonge.obspm.fr/HectordeVegaMedal.pdf

3. The HIGHLIGHTS and CONCLUSIONS of the Meudon Workshop 2016: Warm Dark Matter Astrophysics in Agreement with Observations and keV Sterile Neutrinos is available here: http://chalonge.obspm.fr/Highlights_and_Conclusions_CIAS2016.pdf

On line presentations of the Meudon WDM Workshop

http://chalonge.obspm.fr/Programme_CIAS2016.html

http://chalonge.obspm.fr/Cias_Meudon2016.html

4. The full Programme 2016 and Sessions:

http://chalonge.obspm.fr/Programme2016.html

We thank all again, for having contributed so much to these meetings and we look forward to seeing you again in the next events of this series.

With Compliments and kind regards

http://chalonge.obspm.fr/HdeV.html

Norma G. Sanchez and the Chalonge de Vega School Team

http://chalonge.obspm.fr/.

]]>More details are available on: http://ktwig.fuw.edu.pl/1,1,53,loops17.html

The local organizing committee can be contacted by email on: Loops17[AT]fuw.edu.pl

]]>Publish your next paper in CQG for the chance to be selected for next year’s Highlights.

https://mc04.manuscriptcentral.com/cqg-iop