Seventeenth Marcel Grossmann Meeting

Session

Astrophysics with gravitational waves

GW1

8 Jul 2024, 15:00

Aurum, the ‘Gabriele d’Annunzio’ University and ICRANet

Conveners

Astrophysics with gravitational waves: Monday block 1

• Jose Fernando Rodriguez Ruiz (Universidad Industrial de Santander)

Astrophysics with gravitational waves: Monday block 2

• Jose Fernando Rodriguez Ruiz (Universidad Industrial de Santander)

Astrophysics with gravitational waves: Tuesday block 1

• Jose Fernando Rodriguez Ruiz (Universidad Industrial de Santander)

Astrophysics with gravitational waves: Tuesday block 2

• Jose Fernando Rodriguez Ruiz (Universidad Industrial de Santander)

Description

This parallel session will be devoted to the use of gravitational waves for the study and identification of astrophysical sources such as binary compact objects like double white dwarfs, binary neutron stars, and binary black holes, among others. This covers the relation between gravitational radiation and other forms of radiation (electromagnetic and neutrino emission). Additionally, multiwavelength gravitational wave astronomy will be discussed, focusing on the joint observations from space and ground-based interferometers. Finally, this session will also include the most recent advancements in observational and theoretical studies on how gravitational wave-optics effects at astrophysical scales can be used to identify halos and other types of structures.

499. Lessons, promises, and innovations in synergistic gravitational-wave science

Szabolcs Marka (Columbia University)

08/07/2024, 15:00

Astrophysics with gravitational waves

Talk in a parallel session

The discovery of gravitational waves and their synergistic signatures
has opened immense opportunities for astrophysics. Significant
advancements in gravitational-wave detector technology, both on Earth
and in space, along with progress in electromagnetic and neutrino
observatories, have rapidly expanded our understanding of the cosmos. In
this talk, I will explore how this wholistic...

432. Dissipative effects in matter and metric perturbations: formal analysis

David Díaz-Guerra (Universidad de Salamanca)

08/07/2024, 15:30

Astrophysics with gravitational waves

Talk in a parallel session

Compact objects are usually described using the perfect fluid formalism. However, in astrophysical processes out of local equilibrium, dissipative effects become important to realistically describe the dynamics of the system.
In this work, we present for the first time the gauge-invariant non-spherical perturbations in a dissipative self-gravitating fluid in spherical symmetry. For this we...

220. Conservation, Non-conservation Laws and Gravitational Energy-momentum in General Relativity

Prof. Zhaoyan Wu (Jilin University)

08/07/2024, 16:00

Astrophysics with gravitational waves

Talk in a parallel session

We show that because in a curved spacetime parallel transportations of (r,s)- tensors with r+s>0
depend on paths, one cannot add up (r,s)-tensors at different points to get a definite sum
(r,s)-tensor when r+s>0. However, when restricted to an infinitesimal spacetime region, one still
can add up (r,s)-tensors at different points to get a definite sum (r,s)-tensors, if neglecting
higher...

568. On the maximum mass and stability of differentially rotating neutrons stars

Prof. Dorota Rosinska (OA, University of Warsaw)

08/07/2024, 17:00

Astrophysics with gravitational waves

Talk in a parallel session

The dynamical stability of differentially rotating neutron stars
is of paramount importance in understanding the fate of the post-merger remnant of binary neutron stars mergers and the formation of black holes during core collapse supernovae. We study systematically
the dynamical stability of differentially rotating neutron stars for a broad range of masses, rotation rates and degrees of...

44. Chameleon-induced signatures in polarization of gravitational waves

Prof. Murli Manohar Verma (University of Lucknow)

08/07/2024, 17:30

Astrophysics with gravitational waves

Talk in a parallel session

The chameleon-induced polarization modes of gravitational waves (GWs) are explored in f(R) gravity arising due to scalar field. The chameleon mechanism works strongly in high density regions where mass of the scalar field particle becomes high and the oscillations of the scalar field sharply increase. This produces enhanced scalar modes in addition to the tensor modes of polarization in...

647. Physical Significance of the Constants in the Colliding Plane Gravitational Wave Solutions

Asghar Qadir (None), Kamran Qadir Abbasi (School of Natural Sciences, National University of Science and Technology)

08/07/2024, 18:00

Invited talk in a parallel session

Solutions of the usual wave equation involve two arbitrary constants since it is a
linear second order ordinary differential equation. Physically, these constants represent the amplitude and frequency of the waves. It is not a priori clear that “nonlinear wave equations” must possess two constants as well. However, the exact solutions of the nonlinear Einstein Field Equations for plane and...

23. Dynamical tidal Love numbers of Kerr-like compact objects

Sumanta Chakraborty (Indian Association for the Cultivation of Science)

09/07/2024, 15:00

Astrophysics with gravitational waves

Talk in a parallel session

We develop a framework to compute the tidal response of a Kerr-like compact object in terms of its reflectivity, compactness, and spin, both in the static and the frequency-dependent case. Here we focus on the low-frequency regime, which can be solved fully analytically. We highlight some remarkable novel features, in particular: i) Even in the zero-frequency limit, the tidal Love numbers...

124. Observability of spin precession in the presence of a black-hole remnant kick

Angela Borchers (Max Planck Institute for Gravitational Physics (Albert Einstein Institute))

09/07/2024, 15:30

Astrophysics with gravitational waves

Talk in a parallel session

Remnants of binary black-hole mergers can gain significant recoil or kick velocities due to the anisotropic emission of gravitational waves, which may leave a characteristic imprint in the observed signal. So far, only one gravitational-wave event supports a non-zero kick velocity: GW200129_065458. This signal is also the first to show evidence for spin-precession. For most other...

541. An Effective Field Theory Approach to Gravitational and Electromagnetic Love Numbers of Magnetars

Siddarth Ajith (University of Virginia)

09/07/2024, 16:00

Astrophysics with gravitational waves

Talk in a parallel session

Effective field theory methods have been used in a multitude of applications in gravitational theory, and recent efforts employ such techniques to study tidal interactions. The tidal deformability of stars presents exciting opportunities to analyze both nuclear and gravitational physics due to its dependence on the interior physics of stellar bodies. Information about tidal deformability is...

351. Detectability of exotic object mergers by current generation gravitational wave detectors

Shrobana Ghosh (Max Planck Institute for Gravitational Physics, AEI Hannover)

09/07/2024, 17:00

Astrophysics with gravitational waves

Talk in a parallel session

Over the last decade the international network of gravitational wave detectors (LIGO-Virgo-KAGRA) have detected close to a hundred compact binary mergers. All observations have been consistent with mergers of black holes or neutron stars, but some have been posited as signals generated by the merger of exotic stars. The signal from any compact binary merger would look like that emitted by the...

237. Why CGW is yet to be detected from isolated magnetized rotating neutron stars?

Banibrata Mukhopadhyay (Indian Institute of Science)

09/07/2024, 17:40

Astrophysics with gravitational waves

Talk in a parallel session

There are evidences for neutron stars (NSs) with the rotational frequency of
several 100th of Hz and moderate magnetic fields, though magnetars are slowly
spinning. Hence, if their magnetic and rotating axes are misaligned (nonzero
obliquity angle), hence they are pulsars, then they should be potential
sources for continuous gravitational waves (CGWs), along with their...