本次会议共收录 601 篇报告,分布于 60 个分会。可按标题、作者或正文关键词检索。
共 601 条结果
We investigate the massless scalar field perturbations, including the quasinormal modes spectrum and the ringdown waveform, of regular black hole spacetimes derived within the Asymptotic Safety program. In particular, we discuss the stability of a new class of…
/ Université de Genève/ INFN/GWSC This presentation delves into the study of ‘hairy’ black holes within the framework of Einstein scalar Maxwell gravity and Einstein scalar Gauss-Bonnet theories, with a focus on revealing new scalarized black hole solutions. W…
There is solid theoretical and observational motivation behind the idea of scale invariance as a fundamental symmetry of Nature. We consider a recently proposed classically scale-invariant inflationary model, quadratic in curvature and featuring a scalar field…
We present a series of numerical simulations of the pair creation process in the electrosphere of strange star using the Vlasov–Maxwell equations. The mechanism of pair creation in the electrosphere of compact objects is revisited, paying attention to evaporat…
The ANTARES neutrino telescope has collected data from February 2007 until its shutdown in February 2022. The full ANTARES dataset, including both track-like and shower-like events, has been used to search for both a diffuse, and a galactic neutrino flux. The…
Pulsars are promising sources of gravitational waves (GWs). While asymmetric mass distributions will produce continuos GWs, sudden relocations of small fractions of the internal neutron superfluid could produce transient GW emission. Such rearrangements are be…
Pulsar timing arrays are sensitive to low-frequency gravitational waves with periods of months to decades. They do so by precisely timing a collection of millisecond pulsars, whose extremely stable rotation makes them ideal for measuring perturbations in space…
We present phenomenological analysis of photon lensing in an external gravitational background in the case of photons and neutrinos, and propose a method to incorporate radiative effects in the classical lens equations. The study is performed for a Schwarzschi…
We study the shadows cast by rotating hairy black holes with two non-trivial time-periodic scalar fields having a non-flat Gaussian curvature of the target space spanned by the scalar fields. Such black holes are a viable alternative to the Kerr black hole, ha…
Current images of the supermassive black hole (SMBH) candidates observed at the center of our Galaxy and M87, have opened an unprecedented era to study both, gravity in its strong regime and the very nature of the relativistic sources. Very-long-baseline inter…
Higher-order photon rings can be expected to be detected in a more detailed image of the black hole found in future observations. These rings are lensed images of the luminous matter surrounding the black hole and are formed by photons that loop around it. We…
Fast radio bursts (FRBs) are bright millisecond radio transients observed at extragalactic distances, whose origin is still highly debated. In this presentation, I summarize the key findings from two recent studies that leverage observations conducted with the…
Low angular momentum flows around black holes are likely to form standing shocks during the accretion processes. The shocks possibly encounter instabilities leading to various observational signatures associated with inflows and outflows. In our work, we addre…
Selfdual gravity is a reformulation of general relativity on the phase space of an SL(2,C) gauge theory. As pointed out by Abhay Ashtekar in the mid 1980ies, this reformulation lead to a remarkable simplicity of Hamiltonian GR. Using selfdual variables, the co…
In this talk I will describe novel techniques to simulate the nonlinear collapse of dark matter in the cosmos. I will then present simulations of the abundance of dark matter halos and subhalos as a function of the properties of dark matter. In addition, I wil…
An optically thin advective accretion disk appears to be indispensable in explaining the hard spectral state of black hole sources. We explore, with the help of general relativistic magnetohydrodynamic (GRMHD) simulations, how a large scale stronger magnetic f…
We explore in detail the time-dependent simulation for the evolution of the magnetized main sequence (MS) stars to magnetised white dwarfs (WDs) using the Cambridge Stellar evolution code: STARS. In order to do so, we have appropriately modified the said code…
Nano-electromechanical systems (NEMS), electrostatically driven at their resonance frequency and parametrically pumped by time-dependent dispersion forces, are theoretically expected to display remarkable gain, sensitivity, resolution, and tunability propertie…
To address the problem of time in canonical quantum gravity, one strategy is to use relational observables which results in the use of reference fields or clocks. We explore various ramifications of these clocks in the classical as well as quantum setting. Fir…
Many notions of entropy have been formulated in Physics, from thermodynamics to statistical mechanics and information theory. Bekenstein and Hawking, relying on completely different physical arguments than each other’s, pioneered the idea of gravitational entr…
Cosmic ray acceleration inside compact star clusters has recently received much attention, mainly because of the detection of gamma ray emission from some of such astrophysical sources. Here we focus on the acceleration of nuclei at the wind termination shock…
The Galactic centre region consists of the nuclear stellar disk (NSD), a flat, rotating stellar structure, and the nuclear star cluster (NSC), the densest concentration of stars in the Galaxy. The NSC and NSD are distinct structures of the Milky Way, but also…
In this talk we will present the first study of the spectrum of quasinormal modes of rotating Ellis- Bronnikov wormholes. We compute the spectrum using a spectral decomposition of the metric perturbations on a numerical background. We study the dependence of t…
The landmark detection of a gravitational wave (GW) from the Binary Neutron Star Merger (BNS) GW170817 and its electromagnetic counterparts allowed us to study the Universe in a totally new way. Among the several discoveries made possible by GW170817, we can f…
In this talk, I will discuss the probability distribution of the spins of primordial black holes (PBHs) formed in a matter-dominated universe. For this evaluation, I focus on cosmological perturbations that follow a Gaussian distribution and examine their line…