10,138 research outputs found
New Types of Thermodynamics from -Dimensional Black Holes
For normal thermodynamic systems superadditivity , homogeneity \H and
concavity \C of the entropy hold, whereas for -dimensional black holes
the latter two properties are violated. We show that -dimensional black
holes exhibit qualitatively new types of thermodynamic behaviour, discussed
here for the first time, in which \C always holds, \H is always violated
and may or may not be violated, depending of the magnitude of the black
hole mass. Hence it is now seen that neither superadditivity nor concavity
encapsulate the meaning of the second law in all situations.Comment: WATPHYS-TH93/05, Latex, 10 pgs. 1 figure (available on request), to
appear in Class. Quant. Gra
Universal restrictions to the conversion of heat into work derived from the analysis of the Nernst theorem as a uniform limit
We revisit the relationship between the Nernst theorem and the Kelvin-Planck
statement of the second law. We propose that the exchange of entropy uniformly
vanishes as the temperature goes to zero. The analysis of this assumption shows
that is equivalent to the fact that the compensation of a Carnot engine scales
with the absorbed heat so that the Nernst theorem should be embedded in the
statement of the second law.
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Se analiza la relaci{\'o}n entre el teorema de Nernst y el enunciado de
Kelvin-Planck del segundo principio de la termodin{\'a}mica. Se{\~n}alamos el
hecho de que el cambio de entrop{\'\i}a tiende uniformemente a cero cuando la
temperatura tiende a cero. El an{\'a}lisis de esta hip{\'o}tesis muestra que es
equivalente al hecho de que la compensaci{\'o}n de una m{\'a}quina de Carnot
escala con el calor absorbido del foco caliente, de forma que el teorema de
Nernst puede derivarse del enunciado del segundo principio.Comment: 8pp, 4 ff. Original in english. Also available translation into
spanish. Twocolumn format. RevTe
Discovering New Physics in the Decays of Black Holes
If the scale of quantum gravity is near a TeV, the LHC will be producing one
black hole (BH) about every second, thus qualifying as a BH factory. With the
Hawking temperature of a few hundred GeV, these rapidly evaporating BHs may
produce new, undiscovered particles with masses ~100 GeV. The probability of
producing a heavy particle in the decay depends on its mass only weakly, in
contrast with the exponentially suppressed direct production. Furthemore, BH
decays with at least one prompt charged lepton or photon correspond to the
final states with low background. Using the Higgs boson as an example, we show
that it may be found at the LHC on the first day of its operation, even with
incomplete detectors.Comment: 4 pages, 3 figure
Multi-confocal fluorescence correlation spectroscopy in living cells using a complementary metal oxide semiconductor-single photon avalanche diode array
International audienceLiving cells are heterogeneous and rapidly changing biological samples. It is thus desirable to measure molecular concentration and dynamics in many locations at the same time. In this note, we present a multi-confocal setup capable of performing simultaneous fluorescence correlation spectroscopy measurements, by focusing the spots with a spatial light modulator and acquiring data with a monolithic 32 × 32 single-photon avalanche photodiode array. A post-processing method is proposed to correct cross-talk effects between neighboring spots. We demonstrate the applicability of our system by simultaneously measuring the diffusion of free enhanced Green Fluorescent Protein (eGFP) molecules at nine different points in living cells
Quasi-Homogeneous Thermodynamics and Black Holes
We propose a generalized thermodynamics in which quasi-homogeneity of the
thermodynamic potentials plays a fundamental role. This thermodynamic formalism
arises from a generalization of the approach presented in paper [1], and it is
based on the requirement that quasi-homogeneity is a non-trivial symmetry for
the Pfaffian form . It is shown that quasi-homogeneous
thermodynamics fits the thermodynamic features of at least some
self-gravitating systems. We analyze how quasi-homogeneous thermodynamics is
suggested by black hole thermodynamics. Then, some existing results involving
self-gravitating systems are also shortly discussed in the light of this
thermodynamic framework. The consequences of the lack of extensivity are also
recalled. We show that generalized Gibbs-Duhem equations arise as a consequence
of quasi-homogeneity of the thermodynamic potentials. An heuristic link between
this generalized thermodynamic formalism and the thermodynamic limit is also
discussed.Comment: 39 pages, uses RevteX. Published version (minor changes w.r.t. the
original one
Combinatorial Games with a Pass: A dynamical systems approach
By treating combinatorial games as dynamical systems, we are able to address
a longstanding open question in combinatorial game theory, namely, how the
introduction of a "pass" move into a game affects its behavior. We consider two
well known combinatorial games, 3-pile Nim and 3-row Chomp. In the case of Nim,
we observe that the introduction of the pass dramatically alters the game's
underlying structure, rendering it considerably more complex, while for Chomp,
the pass move is found to have relatively minimal impact. We show how these
results can be understood by recasting these games as dynamical systems
describable by dynamical recursion relations. From these recursion relations we
are able to identify underlying structural connections between these "games
with passes" and a recently introduced class of "generic (perturbed) games."
This connection, together with a (non-rigorous) numerical stability analysis,
allows one to understand and predict the effect of a pass on a game.Comment: 39 pages, 13 figures, published versio
Quantum Gravity Effects in Black Holes at the LHC
We study possible back-reaction and quantum gravity effects in the
evaporation of black holes which could be produced at the LHC through a
modification of the Hawking emission. The corrections are phenomenologically
taken into account by employing a modified relation between the black hole mass
and temperature. The usual assumption that black holes explode around TeV
is also released, and the evaporation process is extended to (possibly much)
smaller final masses. We show that these effects could be observable for black
holes produced with a relatively large mass and should therefore be taken into
account when simulating micro-black hole events for the experiments planned at
the LHC.Comment: 14 pages, 8 figures, extended version of hep-ph/0601243 with new
analysis of final products, final version accepted for publication in J.
Phys.
Is it still worth searching for lepton flavor violation in rare kaon decays?
Prospective searches for lepton flavor violation (LFV) in rare kaon decays at
the existing and future intermediate-energy accelerators are considered. The
proposed studies are complementary to LFV searches in muon-decay experiments
and offer a unique opportunity to probe models with approximately conserved
fermion-generation quantum number with sensitivity superior to that in other
processes. Consequently, new searches for LFV in kaon decays are an important
and independent part of the general program of searches for lepton flavor
violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the
Chicago Flavor Seminar, February 27, 2004. In the new version some misprints
were corrected and some new data for LFV-processes were added. The main
content of the paper was not changed. The paper is published in Yad. Fiz. 68,
1272 (2005
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