193 research outputs found
Is the equivalence for the response of static scalar sources in the Schwarzschild and Rindler spacetimes valid only in four dimensions?
It was shown recently that in four dimensions scalar sources with fixed
proper acceleration minimally coupled to a massless Klein-Gordon field lead to
the same responses when they are (i) uniformly accelerated in Minkowski
spacetime (in the inertial vacuum) and (ii) static in the Schwarzschild
spacetime (in the Unruh vacuum). Here we show that this equivalence is broken
if the spacetime dimension is more than four.Comment: 4 pages, 1 figur
Low-energy sector quantization of a massless scalar field outside a Reissner-Nordstrom black hole and static sources
We quantize the low-energy sector of a massless scalar field in the
Reissner-Nordstrom spacetime. This allows the analysis of processes involving
soft scalar particles occurring outside charged black holes. In particular, we
compute the response of a static scalar source interacting with Hawking
radiation using the Unruh (and the Hartle-Hawking) vacuum. This response is
compared with the one obtained when the source is uniformly accelerated in the
usual vacuum of the Minkowski spacetime with the same proper acceleration. We
show that both responses are in general different in opposition to the result
obtained when the Reissner-Nordstrom black hole is replaced by a Schwarzschild
one. The conceptual relevance of this result is commented.Comment: 12 pages (REVTEX), no figure
Weak decay of uniformly accelerated protons and related processes
We investigate the weak interaction emission of spin-1/2 fermions from
accelerated currents. As particular applications, we analyze the decay of
uniformly accelerated protons and neutrons, and the neutrino-antineutrino
emission from uniformly accelerated electrons. The possible relevance of our
results to astrophysics is also discussed.Comment: 16 pages (REVTEX), 6 figures, to appear in Physical Review
Transition rate of the Unruh-DeWitt detector in curved spacetime
We examine the Unruh-DeWitt particle detector coupled to a scalar field in an
arbitrary Hadamard state in four-dimensional curved spacetime. Using smooth
switching functions to turn on and off the interaction, we obtain a
regulator-free integral formula for the total excitation probability, and we
show that an instantaneous transition rate can be recovered in a suitable
limit. Previous results in Minkowski space are recovered as a special case. As
applications, we consider an inertial detector in the Rindler vacuum and a
detector at rest in a static Newtonian gravitational field. Gravitational
corrections to decay rates in atomic physics laboratory experiments on the
surface of the Earth are estimated to be suppressed by 42 orders of magnitude.Comment: 27 pages, 1 figure. v3: Typos corrected. Published versio
Quantization of the Proca field in the Rindler wedge and the interaction of uniformly accelerated currents with massive vector bosons from the Unruh thermal bath
We canonically quantize the Proca field in the Rindler wedge and compute the
total response rate of a uniformly accelerated current interacting with massive
vector Rindler particles from the Unruh thermal bath. We explicitly verify that
the result obtained is exactly the same as the emission rate of massive vector
particles in the Minkowski vacuum as analyzed by inertial observers. Eventually
our results are interpreted in terms of the interaction of static electrons
coupled to bosons present in Hawking radiation close to the event horizon
of a black hole.Comment: 5 pages, no figure
Why should we care about quantum discord?
Entanglement is a central feature of quantum theory. Mathematical properties
and physical applications of pure state entanglement make it a template to
study quantum correlations. However, an extension of entanglement measures to
mixed states in terms of separability does not always correspond to all the
operational aspects. Quantum discord measures allow an alternative way to
extend the idea of quantum correlations to mixed states. In many cases these
extensions are motivated by physical scenarios and quantum information
protocols. In this chapter we discuss several settings involving correlated
quantum systems, ranging from distributed gates to detectors testing quantum
fields. In each setting we show how entanglement fails to capture the relevant
features of the correlated system, and discuss the role of discord as a
possible alternative.Comment: Written for "Lectures on general quantum correlations and their
applications
Late-Time Tails of Wave Propagation in Higher Dimensional Spacetimes
We study the late-time tails appearing in the propagation of massless fields
(scalar, electromagnetic and gravitational) in the vicinities of a
D-dimensional Schwarzschild black hole. We find that at late times the fields
always exhibit a power-law falloff, but the power-law is highly sensitive to
the dimensionality of the spacetime. Accordingly, for odd D>3 we find that the
field behaves as t^[-(2l+D-2)] at late times, where l is the angular index
determining the angular dependence of the field. This behavior is entirely due
to D being odd, it does not depend on the presence of a black hole in the
spacetime. Indeed this tails is already present in the flat space Green's
function. On the other hand, for even D>4 the field decays as t^[-(2l+3D-8)],
and this time there is no contribution from the flat background. This power-law
is entirely due to the presence of the black hole. The D=4 case is special and
exhibits, as is well known, the t^[-(2l+3)] behavior. In the extra dimensional
scenario for our Universe, our results are strictly correct if the extra
dimensions are infinite, but also give a good description of the late time
behaviour of any field if the large extra dimensions are large enough.Comment: 6 pages, 3 figures, RevTeX4. Version to appear in Rapid
Communications of Physical Review
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