Constructing an exact correspondence between a black hole model and a particular moving mirror trajectory, we investigate a new model that preserves unitarity. The Bogolubov coefficients in 1+1 dimensions are computed analytically. The key modification limits the origin of coordinates (moving mirror) to sub-light asymptotic speed. Effective continuity across the metric ensures that there is no...
Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, astrophysical plasmas are collisionless particle systems residing in stationary states characterized by the so-called kappa distribution function. Empirical kappa distributions have become...
It was proposed recently that the black hole may undergo a transition to the state, where inside the horizon the Fermi surface is formed that reveals an analogy with the recently discovered type II Weyl semimetals. In this scenario the low energy effective theory outside of the horizon is the Standard Model, which describes excitations that reside near a certain point P(0) in momentum space of...
Most of the galaxies seem to harbor supermassive black holes (SMBH) of mass 10^{6-10} times the solar mass in their center. Recent many surveys on the galaxies deep in the sky reveal that such heavy SMBHs have already existed at the redshift 6-7. There have been quite a few research to explain the formation of many SMBH in such an early stage of the Universe. However, there is no definite...
Hamiltonian of the electromagnetic and gravitational fields on asymptotically null space-like surfaces
We find vacuum solutions such that massive gravitons are confined in a local spacetime region by their gravitational energy in asymptotically flat spacetimes in the context of the bigravity theory. We call such self-gravitating objects massive graviton geons. The basic equations can be reduced to the Schroedinger-Poisson equations with the tensor ``wavefunction'' in the Newtonian limit. We...
Primordial Intermediate-Mass Black Holes as Dark Matter
The research on wormhole is an important issue in study of spacetime physics. The wormhole usually consists of exotic matter which satises the are-out condition and violates weak energy condition, even though there have been attempts to construct wormhole with non-exotic matter. There were also solutions of cosmological wormhole model as well as the cosmological black hole solutions. The...
We report the results from a search in Super-Kamiokande for neutrino signals coincident with gravitational-wave events using a neutrino energy range from 3.5 MeV to 100 PeV. We searched for coincident neutrino events within a time window of ±500 s around the gravitational-wave detection time. In this presentation, we report the number of events after in the window and the 90% confidence level...
I apply the Hamiltonian reduction procedure to spacetimes of 4 dimensions without isometries in the (2+2) formalism and find privileged spacetime coordinates in which the physical Hamiltonian is expressed in terms of the conformal two metric and its conjugate momentum. Physical time is the area element of the spatial cross-section of null hypersurfaces, and the physical radial coordinate is...
Decoherence may play a role in the quantum-to-classical transition of primordial cosmological fluctuations. But if it occurs in the early Universe, the interaction with the environment that gives rise to it also changes observable predictions such as the power spectrum from inflation and the amount of non Gaussianities. I will show how this opens up the possibility to observationally probe...
The gravitational instability, responsible for the formation of structure in the Universe, is a Newtonian phenomenon, occurring in the weak-field limit of General Relativity. It occurs at low energies and big radii of a self-gravitating gas when thermal energy can no longer counterbalance self-gravity. I will show that if such an ideal, self-gravitating gas with constant rest mass is...
Wormholes in Galileon theories
The 'projective theory of relativity' is a theory developed by American geometers such as Oswald Veblen and Dutch geometers such as Johannes Schouten, mainly between 1930 and 1935. This theory differs radically from Kaluza-Klein type theories, conformal theories of spacetime or theories such as the 'de Sitter projective relativity' although it shares with these theories geometric aspects in...
In this talk, we present whether the new ekpyrotic scenario can be embedded into ten-dimensional supergravity. We use that the scalar potential obtained from flux compactifications of type II supergravity with sources has a universal scaling with respect to the dilaton and the volume mode. Similar to the investigation of inflationary models, we find very strong constraints ruling out ekpyrosis...
The anti-de Sitter/conformal field theory correspondence and the membrane paradigm have illuminated many aspects of string and field theory, giving key insights into what a quantum theory of gravity might look like, while also providing tools to study a wide range of strongly coupled systems. In essence, these ideas are a statement of the holographic principle: a fundamental observation about...
