Probing Effective Theories of Gravity in Strong Fields and Cosmology, Santa Barbara, USA

Probing Effective Theories of Gravity in Strong Fields and Cosmology
KITP, UC Santa Barbara

Coordinators: Cora Dvorkin, Ira Rothstein, and Thomas Sotiriou
Scientific Advisors: Alessandra Buonanno, Pedro Ferreira, and Steve Giddings

There is strong evidence that General Relativity (GR) is only an effective field theory (EFT). While it is often assumed that the energy scale where the EFT breaks down is near the Planck scale and experimentally inaccessible, tantalizing arguments suggest that GR is not a canonical effective theory.

In particular, the apparent hints of non-locality in black hole evaporation and the small scale associated with the vacuum energy motivate reconsidering EFT ideas in gravity. Given the wealth of data in current and future high precision cosmological surveys, it is necessary to develop a tool kit of theoretically consistent EFTs for analyzing potential deviations from the predictions of GR. The birth of gravitational wave astronomy opens up other avenues for testing gravity in previously unimaginable ways, enabling the study of higher curvature backgrounds as well as black hole horizon physics.

This program is geared towards finding ways to push the boundaries of our knowledge of the EFT of GR by bringing together members of three distinct communities: strong gravity/relativistic astrophysics, cosmology, and EFT.

Primary Application Deadline: August 11th 2019. After that date application will continue to be considered in a rolling basis until the program is filled.

Please apply through the KITP website (link).

Accretion in Strong Gravity, Bad Honnef, Germany

The guiding theme of this seminar is the observation, the modelling and the theoretical description of accretion processes in systems where gravity is strong and nonlinear. Accreting matter are the objects which most closely approach compact objects like black holes or neutron stars and, therefore, are an ideal laboratory to explore the effects of strong gravity. Recently technological developments in observation techniques lead to a strongly improved accuracy in observing accretion discs and related phenomena. This trend will be continued in the next years, for instance with observations of ALMA and the James-Webb telescope, but also with survey telescopes like PanSTARRS or LSST. This development has to be paralleled by the theoretical description and modelling.

Basic open questions in accretion disc physics which will be discussed in this seminar include the description of viscosity and turbulence, in particular in the relativistic context, the effective equations of accretion, evolution of supermassive black holes, accretion discs in generalised theories of gravity, and GRMHD simulations. Summarized, the topics of this seminar are

Observation of astrophysical accretion and related phenomena
The basic equations of accretion and their structure
Applications to accretion discs and the accretion process
Numerical simulation of accretion in strong gravity

Confirmed invited speakers are so far
Prof. Dr. Axel Brandenburg
Prof. Dr. Wolfgang Duschl
Prof. Dr. Andreas Eckart
Prof. Dr. Jose Antonio Font
Prof. Dr. Domenico Giulini
PD Dr. Rodion Groll
Prof. Dr. John Hawley
Dr. Eva Hackmann
Dr. Tobias Illenseer
Prof. Dr. Vladimir Karas
Prof. Dr. Jutta Kunz
Prof. Dr. Claus Laemmerzahl
Prof. Dr. Shin Mineshige
Dr. Monika Moscibrodzka
PD Dr. Volker Perlick
Dr. Daniela Pugliese
Prof. Dr. Luciano Rezzolla
Prof. Dr. Paul Romatschke
Dr. Oldrich Semerak
Dr. Odele Straub

There is no conference fee. The Wilhelm and Else Heraeus-Foundation bears the cost of full-board accommodation for all participants. Up to 75 persons including invited speakers can participate in the seminar. To express your interest in the conference please fill the application form on our website, https://www.we-heraeus-stiftung.de/veranstaltungen/seminare/2019/accretion-in-strong-gravity/application/ or contact us directly.