601 talks across 60 sessions. Search by title, author or full text.
601 results
In recent work [1,2] we have shown that within the natural warm inflationary paradigm (WNI) observational constraints on the primordial power spectrum from the cosmic microwave background (CMB) can be satisfied without going beyond the Planck scale of the effe…
Recent remarkable discoveries, such as Einstein’s gravitational waves, “impossible early”galaxies and quasars, 2D photon Bose-Einstein condensate with rest energy etc. provide a solid experimental and observational basis for “fiery marriage of general relativi…
AstroSat is a multiwavelength astronomy satellite with a suite of instruments facilitating simultaneous observations of cosmic objects in the optical, ultraviolet, soft X-ray, and hard X-ray ranges. The capabilities of these science payloads include a large co…
One of the primary research aims of the Laser Interferometer Space Antenna (LISA) mission is to comprehensively map the Kerr spacetime, a fundamental pursuit in the realm of general relativity. To achieve this goal, it is essential to develop precise tools cap…
Coalescing supermassive black hole binaries (SMBHBs) are the primary source candidates for low frequency gravitational wave (GW) detections, which could bring us deep insights into galaxy evolutions over cosmic time and violent processes of spacetime dynamics.…
The high-energy neutrino observatory ANTARES concluded its 15-year observational campaign in February 2022. Among is primary goals was the identification of the sources of cosmic neutrinos. Throughout its operational lifespan, ANTARES conducted multiple search…
Gravitational waves provide a unique probe to physics in strong gravity regime and dark sector of our universe. In this talk, we will discuss the effects of ultralight fields on binary inspirals, assuming the fields are significantly excited by neutron stars o…
Taiji is a Chinese space mission to detect gravitational waves with frequencies covering the range of 0.1mHz to 1.0Hz by utilizing a triangle of three spacecrafts in orbit around the Sun, which aims to probe the super (intermediate) mass black hole merges and…
Gamma-ray Bursts (GRBs) are one of the most energetic phenomena in the cosmos, whose study probes physics beyond the reach of laboratories on Earth. Yet, our quest to fully unravel the origin of these events and comprehend their underlying physics is far from…
Functional flow equations based on proper-time (PT) regulators have attracted much interest in recent years because of their effectiveness in various non-perturbative situations, for example the exploration of the ordered phase in a scalar theory or non-pertur…
Precision measurements of the cosmic ray D flux are presented as function of rigidity from 1.9 to 21 GV, based on 21 million D nuclei. We observed that over the entire rigidity range D exhibit nearly identical time variations with p, 3 He, and 4 He fluxes. Abo…
Regular black holes have become a popular alternative to the singular mathematical black holes predicted by general relativity as they circumvent mathematical pathologies associated with the singularity while preserving crucial black hole features such as the…
In this work, we investigate the global structure of shock-induced general relativistic magnetohydrodynamic (GRMHD) accretion flows around a Kerr black hole, where the disk is threaded by the radial (br ) and the toroidal (bϕ ) magnetic fields. In doing so, we…
On August 17, 2017, the joint detection of GW170817 and GRB 170817A opened the era of multimessenger astronomy with gravitational waves (GWs) and provided the first direct probe that at least some binary neutron star (BNS) mergers are progenitors of short gamm…
Institute for Theoretical Physics, University of Warsaw, Pasteura 5, PL-02-093 Warsaw, Poland; Department of Astronomy, Williams College, Williamstown, MA 01267, USA 3 INAF-IASF, Sezione di Bologna, via Gobetti 101, I-40129 Bologna, Italy Using a new sample co…
Magnetars are isolated young neutron stars that exhibit the most intense magnetic fields known in the Universe and are characterized by a wide variety of high-energy emissions. The birth of rapidly rotating magnetars is also a promising scenario to power outst…
Magnetars are isolated young neutron stars that exhibit the most intense magnetic fields known in the Universe and are characterized by a wide variety of high-energy emissions. The birth of rapidly rotating magnetars is also a promising scenario to power outst…
The X-ray afterglow of many gamma-ray bursts (GRBs) exhibits a plateau phase, which may be related to continued activities of the central engine. It has been found that there exists a so-called L–T–E correlation for these GRBs, which involves three key paramet…
(pdf version attached) Ever since the observation of GW170817 provided evidence for binary neutron star mergers as sources of gravitational waves and other transient emissions such as short gamma-ray bursts, the development of electromagnetically informed grav…
We present an approach to field quantization in curved spacetime which is based on the De Donder- Weyl Hamiltonian theory where space and time dimensions are treated on an equal footing. This leads to a description in terms of Clifford algebra valued wave func…
We revisit basic problems of classical Friedmann-Lemaître cosmology that motivate the idea of cosmological inflation in light of modern ideas on quantum geometry. Classical cosmology assumes the validity of General Relativity with its smooth Riemannian spaceti…
Gravitational waves propagate at the speed of light. If we take an ultra-short distributional pulse of gravitational radiation, the resulting wavefront will move along a co-dimension one light-like (null) surface in spacetime. The question of how to describe t…
It is a longstanding conjecture that spacetime is emergent from an unknown substructure on an ultramicroscopic scale. While there are many competing models of this sort, a generic question is whether the existence of a fundamental length has any observable con…
We present a systematic approach to the kinematics of quantum-reduced loop gravity, a model originally proposed by Alesci and Cianfrani as an attempt to probe the physical implications of loop quantum gravity. In order to implement the quantum gauge-fixing pro…
Quasi Periodic Eruptions (QPEs) are a puzzling X-ray phenomena recently discovered in a number of sources with similar properties. In this talk, I am going to present a theoretical model that is able to reproduce their phenomenology in at least 4 sources. The…