Holography for Astrophysics and Cosmology

Contribution List

1. Gravitational waves from cosmological phase transitions

Thomas Konstandin

19/10/2022, 09:00

I will discuss the state-of-the-art of predicting and experimentally testing a stochastic background of gravitational waves produced by cosmological first-order phase transitions. I focus on recent developments in understanding the dynamics of the primordial fluid after percolation and how to connect simulation results to observations and model building.

2. AdS/CAP

David Mateos

19/10/2022, 11:00

The discovery of gravitational waves has opened a new experimental window into the Universe. The fact that the relevant physics is often out of equilibrium offers a golden opportunity for holography to make a unique impact on cosmology and astrophysics. I will review recent progress in this direction, with a focus on cosmological phase transitions and neutron star mergers. I will also discuss...

3. Holographic Effective Actions and Bubble Nucleation

Carlos Hoyos

19/10/2022, 14:00

A first order phase transition in the early Universe could lead to an observable signal of gravitational waves. When the the sector undergoing the transition is strongly coupled ordinary field theory calculations become significantly harder, but holographic models may be useful to circumvent this issue. We discuss how to obtain an effective action from holographic models capturing the dynamics...

4. A Phases of holographic nuclear matter which are phases of crystals of instantons

Cobi Sonnenschein

19/10/2022, 16:00

Nuclear at large number of colors is necessarily in a solid phase. I will explain this fact. In particular holographic nuclear matter takes the form of a crystal of instantons of the flavor group. In this talk I will briefly review the passage from holographic baryonic matter in the Sakai-Sugimoto model to crystansl of instantons. The analysis of the three- dimensional crystal structures and...

13. New sources of GW

Mikel Sanchez Garitaonandia

19/10/2022, 16:30

With the advent of GW astronomy, a new exciting window into studying matter has been opened. It is then crucial to perform a search for possible GW sources. In this talk I will present two new sources of GW emission from first order phase transitions: the spinodal instability and phase transitions in neutron star mergers. The former is relevant in the context of cosmology, when bubble...

14. Partial deconfinement

Jack Holden

19/10/2022, 17:00

In large-$N$ gauge theories, evidence has emerged recently that between confined and deconfined phases a partially-deconfined phase can appear, in which only a subset of colours deconfine. The existence of such a phase has implications for the map between degrees of freedom under gauge/gravity duality and black hole phase diagrams, where a counterpart to the partially-deconfined saddle should...

5. Holography for QFTs in de Sitter

Kostas Skenderis

20/10/2022, 09:00

I will discuss how to set up holography for QFTs in de Sitter by studying AdS gravity coupled to a scalar field in the bulk. The talk will start with a discussion of subtleties regarding the identification of the conformal boundary of asymptotically locally AdS spacetimes. I will then focus on the case the boundary geometry is de Sitter and compute the 1- and 2-point function of the dual QFT...

6. Living at the tip of the throat

Ivonne Zavala

20/10/2022, 11:00

Warped throats arise generically in string theory flux compactifications, which play a crucial role in the process of moduli stabilisation. Therefore, these non-trivial geometries provide novel avenues to explore cosmological paradigms, such as early and late time acceleration, namely inflation and dark energy. I will discuss recent developments on phenomenological applications of warped...

7. Quantum holographic (in)stability of de Sitter space

Elias Kiritsis

20/10/2022, 14:00

Classical gravity coupled to a holographic CFT_4 (matter) is considered. The effect of the quantum dynamics of matter on gravity is studied around de Sitter space. The structure of the graviton propagator is modified and non-trivial poles appear due to matter quantum effects.
The position and residues of such poles are mapped as a function of the relevant parameters, the number of colors $N$...

15. Holography and neutrino transport in dense media

Edwan Préau

20/10/2022, 14:30

The cooling of young neutron stars happens mainly via emission of neutrinos from the core. The modeling of this process requires the knowledge of the neutrino weak interaction rates with the dense QCD matter inside the star. This can be formalized into the calculation of the retarded 2-point correlation function for the chiral currents, which is a strongly coupled problem. The holographic...

16. Novel aspects in relativistic hydrodynamics

Yago Bea

20/10/2022, 15:00

Recent studies point in the direction that viscosity might be relevant in neutron star mergers. The usual approach to introduce viscosity in relativistic systems, MIS-like theories, has been recently shown to present some limitations. In particular, it presents limitations when dealing with shocks, features present in neutron star mergers. The first-order viscous theory of hydrodynamics...

9. Quark matter cores in massive neutron stars

Aleksi Vuorinen

21/10/2022, 09:00

I will discuss recent model-independent efforts to discover deconfined matter in the cores of massive neutron stars. Such progress is made possible on one hand by the availability of accurate observational information from neutron-star mass-radius and tidal deformability measurements, and on the other hand by the impressive progress in robust first-principles calculations in chiral effective...

10. Holography of novel QCD phases at high density and neutron stars

Nick Evans

21/10/2022, 11:00

The D3/probe D7 system provides a powerful tool for computing the properties of quarks at strong coupling including with temperature, density and chiral symmetry inducing interactions. When applied to neutron stars the system suggests that quark cores are too soft to support neutron stars. We investigate how one might escape that conclusion by looking at the effects of the running coupling and...

12. Holographic Floquet on the brane

Alfonso Ramallo

21/10/2022, 14:00

After reviewing briefly the basics of Floquet engineering, in which quantum systems are manipulated in a controlled way by using time-periodic external fields, we will analyze with holographic techniques the response of a (2+1)-dimensional gauge theory to an external rotating external electric field. This system has a non-equilibrium phase diagram with Floquet condensates in which there is a...

17. Flavored anisotropic black holes

Jose Manuel Penin Ascariz

21/10/2022, 14:30

We construct a black hole geometry dual to a (2+1)-dimensional defect in an ambient (3+1)-dimensional gauge theory at non-zero temperature and quark density. The geometry is a solution to the equations of motion of type IIB supergravity with brane sources, a low energy limit of an intersection of stacks of color D3-branes and flavor D5-branes. We consider the case in which the number of...