GRG Editor’s Choice: Notable articles in General Relativity & Gravitation

In each volume of the journal General Relativity & Gravitation, a few papers are marked as “Editor’s Choice”. The primary criteria is original, high quality research that is of wide interest within the community.

Tanatarov, I.V. & Zaslavskii, O.B., Collisional super-Penrose process and Wald inequalities, Gen Relativ Gravit (2017) 49: 119. https://doi.org/10.1007/s10714-017-2281-0

Abstract:
We consider collision of two massive particles in the equatorial plane of an axially symmetric stationary spacetime that produces two massless particles afterwards. It is implied that the horizon is absent but there is a naked singularity or another potential barrier that makes possible the head-on collision. The relationship between the energy in the center of mass frame Ec.m. and the Killing energy E measured at infinity is analyzed. It follows immediately from the Wald inequalities that unbounded E is possible for unbounded Ec.m. only. This can be realized if the spacetime is close to the threshold of the horizon formation. Different types of spacetimes (black holes, naked singularities, wormholes) correspond to different possible relations between Ec.m. and E. We develop a general approach that enables us to describe the collision process in the frames of the stationary observer and zero angular momentum observer. The escape cone and escape fraction are derived. A simple explanation of the existence of the bright spot is given. For the particular case of the Kerr metric, our results agree with the previous ones found in Patil et al. (Phys Rev D 93:104015, 2016).

Sakovich, A. & Sormani, C., Almost rigidity of the positive mass theorem for asymptotically hyperbolic manifolds with spherical symmetry, Gen Relativ Gravit (2017) 49: 125. https://doi.org/10.1007/s10714-017-2291-y

Abstract:
We use the notion of intrinsic flat distance to address the almost rigidity of the positive mass theorem for asymptotically hyperbolic manifolds. In particular, we prove that a sequence of spherically symmetric asymptotically hyperbolic manifolds satisfying the conditions of the positive mass theorem converges to hyperbolic space in the intrinsic flat sense, if the limit of the mass along the sequence is zero.

GRG Editor’s Choice: Cosmological solutions with charged black holes

Bibi, R., Clifton, T. and Durk, J., Cosmological solutions with charged black holes, Gen Relativ Gravit (2017) 49: 98. doi:10.1007/s10714-017-2261-4

Open Access | Editor’s Choice (Research Article)
First Online: 30 June 2017

In each volume of the journal General Relativity & Gravitation, a few papers are marked as “Editor’s Choice”. The primary criteria is original, high quality research that is of wide interest within the community.

Abstract:
We consider the problem of constructing cosmological solutions of the Einstein–Maxwell equations that contain multiple charged black holes. By considering the field equations as a set of constraint and evolution equations, we construct exact initial data for N charged black holes on a hypersphere. This corresponds to the maximum of expansion of a cosmological solution, and provides sufficient information for a unique evolution. We then consider the specific example of a universe that contains eight charged black holes, and show that the existence of non-zero electric charge reduces the scale of the cosmological region of the space. These solutions generalize the Majumdar–Papapetrou solutions away from the extremal limit of charged black holes, and provide what we believe to be some of the first relativistic calculations of the effects of electric charge on cosmological backreaction.

The authors:
Jessie Durk is currently a PhD student, researching theoretical cosmology with Dr Timothy Clifton, lecturer at Queen Mary University London. Rashida Bibi is a faculty member of the International Islamic University, Islamabad.

Living Reviews in Relativity: new article and website

The open-access journal Living Reviews in Relativity has published a new review article on 4 April 2017:

Joseph D. Romano and Neil. J. Cornish, Detection methods for stochastic gravitational-wave backgrounds: a unified treatment, Living Rev Relativ (2017) 20:2. doi:10.1007/s41114-017-0004-1

We are also happy to announce that the new Living Reviews community portal (http://www.livingreviews.org) was recently relaunched.

With this common entry point to research and review journals in physics and astronomy, three communities will be able to find associated journals, highlighted articles, and related news ‘just a click away’.

We present Springer’s original research journals along with the Living Reviews open-access series as partner journals serving researchers in relativity, solar physics, and computational astrophysics.

This milestone marks also the completion of the Living Reviews journals’ content transfer from its previous publishing platform to SpringerLink, during which all articles have been retro-digitized and are now also available in standard XML/HTML with embedded MathJax.

New textbook (in German): “Spezielle und allgemeine Relativitaetstheorie fuer Bachelorstudenten”, by Reinhard Meinel

A new textbook published by Springer-Verlag Berlin Heidelberg. Its first two parts give an elementary introduction to special and general relativity. The third part (“Ergaenzungen fuer Fortgeschrittene”) deals with mathematical methods that can be used, for example, to solve the black hole boundary value problem of the stationary and axially symmetric Einstein-Maxwell equations leading to the Kerr-Newman solution in a unique and straightforward manner.

GRG Editor’s Choice articles free to read

On the occasion of the upcoming GR21 conference, selected articles from the journal General Relativity and Gravitation are now free-to-read until July 31, 2016:
http://bit.ly/294Uh4J

In each volume, a few papers are marked as “Editor’s Choice”. The primary criteria is original, high quality research that is of wide interest within the community. We would also like to introduce Springer’s new article interface, optimized for easy reading on mobile devices.

General Relativity and Gravitation is a journal devoted to all aspects of modern gravitational science, and published under the auspices of the ISGRG. The journal publishes research letters and papers, invited review articles on all theoretical and experimental aspects of modern general relativity and gravitation, as well as book reviews and historical articles of special interest.

We welcome your submissions, and see you at GR21!

Living Reviews in Computational Astrophysics: first articles online

Living Reviews in Computational Astrophysics is a new peer-reviewed open-access journal. Founded and supported by the Max Planck Institute for Astrophysics in Garching, the new member of the pioneering Living Reviews family is published by Springer International.

The journal aims at offering a comprehensive survey of research in computational astrophysics that physicists will know is up-to-date and reliable. Living Reviews is unique in that it only publishes high-quality review articles whose authors commit to update them regularly. This is the meaning of the word “living” in the journal’s title.

Living Reviews in Computational Astrophysics now started publication with its first two review articles: “SPH Methods in the Modelling of Compact Objects” by Stephan Rosswog and “Large Eddy Simulations in Astrophysics” by Wolfram Schmidt.

Please find the abstracts and further details below.

—————
Stephan Rosswog
SPH Methods in the Modelling of Compact Objects

FULL ARTICLE AT:
http://www.livingreviews.org/lrca-2015-1

ABSTRACT:
We review the current status of compact object simulations that are based on the smooth particle hydrodynamics (SPH) method. The first main part of this review is dedicated to SPH as a numerical method. We begin by discussing relevant kernel approximation techniques and discuss the performance of different kernel functions. Subsequently, we review a number of different SPH formulations of Newtonian, special- and general relativistic ideal fluid dynamics. We particularly point out recent developments that increase the accuracy of SPH with respect to commonly used techniques. The second main part of the review is dedicated to the application of SPH in compact object simulations. We discuss encounters between two white dwarfs, between two neutron stars and between a neutron star and a stellar-mass black hole. For each type of system, the main focus is on the more common, gravitational wave-driven binary mergers, but we also discuss dynamical collisions as they occur in dense stellar systems such as cores of globular clusters.

—————
Wolfram Schmidt
“Large Eddy Simulations in Astrophysics””

FULL ARTICLE AT:
http://www.livingreviews.org/lrca-2015-2

ABSTRACT:
In this review, the methodology of large eddy simulations (LES) is introduced and applications in astrophysics are discussed. As theoretical framework, the scale decomposition of the dynamical equations for neutral fluids by means of spatial filtering is explained. For cosmological applications, the filtered equations in comoving coordinates are also presented. To obtain a closed set of equations that can be evolved in LES, several subgrid-scale models for the interactions between numerically resolved and unresolved scales are discussed, in particular the subgrid-scale turbulence energy equation model. It is then shown how model coefficients can be calculated, either by dynamic procedures or, a priori, from high-resolution data. For astrophysical applications, adaptive mesh refinement is often indispensable. It is shown that the subgrid-scale turbulence energy model allows for a particularly elegant and physically well-motivated way of preserving momentum and energy conservation in adaptive mesh refinement (AMR) simulations. Moreover, the notion of shear-improved models for inhomogeneous and non-stationary turbulence is introduced. Finally, applications of LES to turbulent combustion in thermonuclear supernovae, star formation and feedback in galaxies, and cosmological structure formation are reviewed.

UPCOMING ARTICLES AT:
http://computastrophys.livingreviews.org/Articles/upcoming.html

New book: “Superradiance” by R. Brito, V. Cardoso and P. Pani

Dear hyperspace community,

We would like to announce the publication of a new book on the physics of superradiance, co-authored by R. Brito, V. Cardoso and P. Pani, Springer Lecture Notes in Physics vol. 906 (2015).

Details of the book are available at
http://link.springer.com/book/10.1007%2F978-3-319-19000-6

or in Amazon

http://www.amazon.com/Superradiance-Extraction-Black-Hole-Implications-Astrophysics/dp/3319189999

This volume gives a unified picture of the multifaceted subject of superradiance, with a focus on recent developments in the field, ranging from fundamental physics to astrophysics. The book covers all our current understanding on the physics of the amplification of waves by a medium, including classical effects such as the Cherenkov effect. The main body of the book deals with superradiance in black hole physics, with important applications in astrophysics and particle physics. Each chapter ends with a list of outstanding open problems and future directions.

Best wishes to all,

Richard Brito, Vitor Cardoso, Paolo Pani

New book: “Cosmological and Black Hole Apparent Horizons” by V. Faraoni

Dear hyperspace community,

I would like to announce the publication of a new book which may be of interest to some of you: “Cosmological and Black Hole Apparent Horizons” by V. Faraoni, 199 pages, 8 figures,
Springer Lecture Notes in Physics vol. 907 (2015)
ISBN:978-3-319-19239-0 (Print) 978-3-319-19240-6 (Online)
Details of the book are available at
http://link.springer.com/book/10.1007/978-3-319-19240-6

Best wishes to all,

Valerio Faraoni
Physics Department
Bishop’s University
Sherbrooke, Quebec, Canada

Living Reviews move to Springer

Springer acquires three pioneering open access journals from the Max Planck Society

Springer has acquired the three pioneering ‘living’ open access journals: Living Reviews in Relativity, Living Reviews in Solar Physics, and the recently launched journal Living Reviews in Computational Astrophysics from the Max Planck Society. The Living Reviews will complement Springer’s open access journal portfolio.

New books: Two Volumes from the Prague conference “Relativity and Gravitation—100 years after Einstein in Prague”

”Relativity and Gravitation–100 years after Einstein in Prague”, was the name of the conference held in Prague on June 25-29, 2012, inspired by the title, date, and significance of the last of Einstein’s Prague papers. The aim of the conference was to review the present status of the general theory of relativity (both classical and quantum) and its applications in cosmology and astrophysics from a broad perspective. The second aim was to present the newest results in each of these fields.

The first volume “General Relativity, Cosmology and Astrophysics–Perspectives 100 years after Einstein’s stay in Prague” (J. Bicak and T. Ledvinka eds.) is included in the Springer series Fundamental Theories of Physics, No. 177.

The articles included in this Volume represent a broad and highly qualified view on the present state of general relativity, quantum gravity, and their cosmological and astrophysical implications. As such, it may serve as a valuable source of knowledge and inspiration for experts in these fields, as well as an advanced source of information for young researchers. The contents are divided into four broad parts: (i) Gravity and Prague, (ii) Classical General Relativity, (iii) Cosmology and Quantum Gravity, and (iv) Numerical Relativity and Relativistic Astrophysics. Approaching soon the centenary of Einstein’s famous theory, this volume offers a precious overview of the path done by the scientific community in this field in the last century, defining the challenges of the next 100 years.

The second volume “Relativity and Gravitation–100 Years After Einstein in Prague”, (J. Bicak and T. Ledvinka eds.) is included in the Springer Proceedings in Physics, No. 157.

This volume includes abstracts of the plenary talks (contained in the first volume) and 82 full texts of contributed talks and articles based on the posters presented at the conference. These describe primarily original results of the authors from 31 countries. The contents are divided into three broad parts: (i) Classical General Relativity, (ii) Cosmology and Relativistic Astrophysics, and (iii) Quantum Fields and Quantum Gravity.

The tables of contents, some sample pages and further information can be obtained from the following links:

http://www.springer.com/physics/theoretical%2C+mathematical+%26+computational+physics/book/978-3-319-06348-5
http://www.springer.com/physics/theoretical%2C+mathematical+%26+computational+physics/book/978-3-319-06760-5

Major new reference work: Springer Handbook of Spacetime

Edited by Abhay Ashtekar and Vesselin Petkov, the long-awaited Springer Handbook of Spacetime is now available, also as an eBook. It is dedicated to the ground-breaking paradigm shifts embodied in the two relativity theories, and describes in detail the profound reshaping of physical sciences they ushered in. In a single volume it includes chapters on foundations, on the underlying mathematics, on physical and astrophysical implications, experimental evidence and cosmological predictions, as well as discussing efforts to unify general relativity and quantum physics. The Handbook can be used as a desk reference by researchers in a wide variety of fields, not only by specialists in relativity but also by researchers in related areas that either grew out of, or are deeply influenced by, the two relativity theories: cosmology, astronomy and astrophysics, high energy physics, quantum field theory, mathematics, and philosophy of science. It should also serve as a valuable resource for graduate students and young researchers entering these areas, and for instructors who teach courses on these subjects.
The Handbook is divided into six parts: Part A: Introduction to Spacetime Structure. Part B: Foundational Issues. Part C: Spacetime Structure and Mathematics. Part D: Confronting Relativity theories with observations. Part E: General relativity and the universe. Part F: Spacetime beyond Einstein.

New book: “Special Relativity in General Frames” by Eric Gourgoulhon

Special Relativity in General Frames: From Particles to Astrophysics
Eric Gourgoulhon
Springer, 2013
784 pages

Special relativity is presented by adopting a four-dimensional point of view from the start. A distinctive feature of the book is that it doesn’t restrict itself to inertial frames and considers accelerated and rotating observers. It is thus possible to treat physical effects such as the Thomas precession or the Sagnac effect in a simple yet precise manner. In the final chapters, more advanced topics like tensorial fields in spacetime, exterior calculus, relativistic hydrodynamics and relativistic gravity are addressed. Illustrated by 178 figures and enriched by many historical notes, this book also presents many applications of special relativity, ranging from particle physics (accelerators, particle collisions, quark-gluon plasma) to astrophysics (relativistic jets, active galactic nuclei), and including practical applications (Sagnac gyrometers, synchrotron radiation, GPS). In addition, the book provides some mathematical developments, such as the detailed analysis of the Lorentz group and its Lie algebra.

Contents:
1. Minkowski Spacetime
2. Worldlines and Proper Time
3. Observers
4. Kinematics 1: Motion with Respect to an Observer
5. Kinematics 2: Change of Observer
6. Lorentz Group
7. Lorentz Group as a Lie Group
8. Inertial Observers and Poincaré Group
9. Energy and Momentum
10. Angular Momentum
11. Principle of Least Action
12. Accelerated Observers
13. Rotating Observers
14. Tensors and Alternate Forms
15. Fields on Spacetime
16. Integration in Spacetime
17. Electromagnetic Field
18. Maxwell Equations
19. Energy-Momentum Tensor
20. Energy-Momentum of the Electromagnetic Field
21. Relativistic Hydrodynamics
22. What about Relativistic Gravitation?
A. Basic Algebra
B. Web Pages
C. Special Relativity Books

More details on http://relativite.obspm.fr/sperel/

New book: “The General Theory of Relativity: A Mathematical Exposition” by Anadijiban Das and Andrew DeBenedictis

Anadijiban Das and Andrew DeBenedictis
“The General Theory of Relativity: A Mathematical Exposition”
705 pages, 105 figures.
Springer (2012).

“The General Theory of Relativity: A Mathematical Exposition” will serve readers as a modern mathematical introduction to the general theory of relativity. Throughout the book, examples, worked-out problems, and exercises (with hints and solutions) are furnished. Topics in this book include, but are not limited to:

– tensor analysis,
– the special theory of relativity,
– the general theory of relativity and Einstein’s field equations,
– spherically symmetric solutions and experimental confirmations,
– static and stationary space-time domains,
– black holes,
– cosmological models,
– algebraic classifications and the Newman-Penrose equations,
– the coupled Einstein-Maxwell-Klein-Gordon equations,
– appendices covering mathematical supplements and special topics,

Mathematical rigor, yet very clear presentation of the topics make this book a unique text for both university students and research scholars.

For full publication details please see:
http://www.springer.com/physics/theoretical%2C+mathematical+%26+computational+physics/book/978-1-4614-3657-7
or
http://www.sfu.ca/~adebened/grbook/

New book: “3+1 Formalism in General Relativity” by Eric Gourgoulhon

3+1 Formalism in General Relativity: Bases of Numerical Relativity

Eric Gourgoulhon
Springer, 2012
294 pages

Contents:
1. Introduction
2. Basic Differential Geometry
3. Geometry of Hypersurfaces
4. Geometry of Foliations
5. 3+1 Decomposition of Einstein Equation
6. 3+1 Equations for Matter and Electromagnetic Field
7. Conformal Decomposition
8. Asymptotic Flatness and Global Quantities
9. The Initial Data Problem
10. Choice of Foliation and Spatial Coordinates
11. Evolution Schemes
A. Conformal Killing Operator and Conformal Vector Laplacian
B. Sage Codes

More details at http://relativite.obspm.fr/3p1

Free access to all papers published in “Gravitation and Cosmology”

Free full text versions of all papers published in the international journal “Gravitation and Cosmology” (Grav. Cosmol.) during 1995-2007 are now at the site of the Russian Gravitational Society http://www.rgs.da.ru (or http://www.rgs.vniims.ru). Click “welcome”, then “Gravitation and Cosmology”, then “old issues”, then issue (volume, number), then title of the paper, then in the last line “here”.

As from 2008 the journal “Gravitation and Cosmology” is distributed by Springer, contents of all issues and abstracts of papers published in 2008-2009 in the journal may be found at the site:
http://www.springerlink.com/content/120954/

All other info and subscription details are at the site:
http://www.springer.com/astronomy/general+relativity/journal/12267
Please, recommend the subscription to this journal of your institute or university library for 2010.

Best regards,
Prof. Vitaly Melnikov,
Editor-in-Chief