arXiv subjects
Publications and source records attributed to Slava Emelyanov.
We show at one-loop approximation that the QED photon acquires a negative gauge-invariant mass-squared in the near-horizon region of an evaporating Schwarzschild black hole. This result may imply that information about the inner structure of evaporating black holes is accessible, even without invoking the modification of the basic QFT and GR principles.
The black-hole evaporation implies that the quantum-field propagators in a local Minkowski frame acquire a correction, which gives rise to this process. The modification of the propagators causes, in turn, non-trivial local effects due to the radiative/loop diagrams in non-linear QFTs. In particular, there should be imprints of the evaporation in QED, if one goes beyond the tree-level approximation. Of special interest in this respect is the region near the black-hole horizon, which, already at tree level, appears to show highly non-classical features, e.g., negative energy density and energy flux into the black hole.
We study massless scalar theory with the quartic self-interacting term far away from and near to evaporating and spherically symmetric black hole. We propose a principle of how to define the physical notion of particle in curved space-time. Employing this definition, we compute one-loop correction to the self-energy and coupling constant of the scalar field near the horizon in the freely-falling frame. We find that the coupling constant becomes slightly stronger near to the horizon. We also find that the term in the 2-point function that is (partially) responsible for the black-hole evaporation corresponds to the sub-leading correction to the Feynman propagator whose pole structure is of the leading order.
We find within the framework of quantum electrodynamics that there exists the screening effect of static magnetic field that is induced by evaporating black holes.
We employ quantum kinetic theory to investigate local quantum physics in the background of spherically symmetric and neutral black holes formed through the gravitational collapse. For this purpose in mind, we derive and study the covariant Wigner distribution function $\mathcal{W}(x,p)$ near to and far away from the black-hole horizon. We find that the local density of the particle number is negative in the near-horizon region, while the entropy density is imaginary. These pose a question whether kinetic theory is applicable in the near-horizon region. We elaborate on that and propose a possible interpretation of how this result might nevertheless be self-consistently understood.
We compute the value of effective photon mass $m_γ$ at one-loop level in QED in the background of small ($10^{10}\,\text{g} \lesssim M \ll 10^{16}\,\text{g}$) spherically symmetric black hole in asymptotically flat spacetime. This effect is associated with the modification of electron/positron propagator in presence of event horizon. Physical manifestations of black-hole environment are compared with those of hot neutral plasma. We estimate the distance to the nearest black hole from the upper bound on $m_γ$ obtained in the Coulomb-law test. We also find that corrections to electron mass $m_e$ and fine structure constant $α$ at one-loop level in QED are negligible in the weak gravity regime.
It is shown that the correspondence principle and the holographic principle are incompatible in the background of an eternal Schwarzschild-anti-de Sitter geometry. The argument is based on the observation that algebraic structures of local quantum field and CFT operators are not equivalent. This implies, in particular, the bulk CFT must be singular near the black-hole horizon. A CFT Hilbert space representation is elaborated which may correspond to the AdS black hole in the dual theory.
One might expect far away from physical black holes that quantum field quantisation performed in Minkowski space is a good approximation. Indeed, all experimental tests in particle colliders reveal no deviations so far. Nevertheless, the black holes should leave certain imprints of their presence in quantum processes. In this paper, we shall discuss several local imprints of small, primordial evaporating black holes in quantum electrodynamics in the weak gravity regime. Physically this can be interpreted as being macroscopic manifestations of vacuum fluctuations.
We study the influence of black-hole evaporation on light propagation. The framework employed is based on the non-linear QED effective action at one-loop level. We show that the light-cone condition is modified for low-energy radiation due to black-hole evaporation. We discuss conditions under which the phase velocity of this low-energy radiation is greater than $c$. We also compute the modified light-deflection angle, which turns out to be significantly different from the standard GR value for black-hole masses in the range $M_\text{Pl} \ll M \lesssim 10^{19}\;M_\text{Pl}$.
This paper shows a way of how one may resolve the non-unitarity problem in black-hole physics without modifications of the basic principles of local quantum field theory.
A question is studied whether an observer can discover quantum gravity being in the semi-classical regime. It is shown that it is indeed possible to probe a certain quantum gravity effect by employing an appropriately designed detector. The effect is related to the possibility of having topologically inequivalent geometries at once in the path integral approach. A CFT state which is expected to describe the eternal AdS black hole in the large N limit is discussed. It is argued under certain assumptions that the black hole boundary should be merely a patch of the entire AdS boundary. This leads then to a conclusion that that CFT state is the ordinary CFT vacuum restricted to that patch. If existent, the bulk CFT operators can behave as the ordinary semi- classical quantum field theory in the large N limit in the weak sense.
This paper studies a recently proposed relation between the emergence of bulk locality in AdS/CFT and the theory of quantum error correction. We show that if this relation is indeed realized in AdS/CFT, then bulk covariance is broken in the semi-classical limit.
A free hermitian conformal field theory is considered in Minkowski, de Sitter and anti-de Sitter spacetimes. The first part of the paper studies spacetime inversion and conformal inversion, wherein their role in the field quantization is elucidated in those spaces. The second part of the paper is concerned with the non-unitary evolution of detector's state. Several examples of such processes are provided with a clarification of how the unitarity is preserved with still having well-known thermal effects.
Certain local thermal observables are considered in well-known examples of spatially open FRW spaces: Milne, open de Sitter and anti de Sitter as well as Einstein static universes. Another value for fixing the ambiguity in defining the Wick square and, hence, the local temperature is motivated in the last example. Physical consequences of that choice are discussed for static and conformal vacua in those spaces.
A quantum scalar field in anti de Sitter space is considered in two coordinate systems: static and FRW-like ones. It is shown that quantum vacua corresponding to each of these coordinatizations are not unitary equivalent. A choice of a physical ground state between these vacua is discussed under different setups.