172 research outputs found
Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems
A nonequilibrium distribution function of microscopic thermal current is
studied by a direct numerical simulation in a thermal conducting steady state
of particle systems. Two characteristic temperatures of the thermal current are
investigated on the basis of the distribution. It is confirmed that the
temperature depends on the current direction; Parallel temperature to the
heat-flux is higher than antiparallel one. The difference between the parallel
temperature and the antiparallel one is proportional to a macroscopic
temperature gradient.Comment: 4 page
Morphology Control of Zn-SiO2 Composite Films Electrodeposited from Aqueous Solution Containing Quaternary Ammonium Cations
Zn-SiO2 alloys were electrodeposited from acidic aqueous solution containing cationic surfactants such as diallyl-dimethyl-ammonium chloride, trimethyl-tetradecyl-ammonium chloride, trimethyl-stearyl-ammonium chloride and dimethyl-distearyl-ammonium chloride. Zn-SiO2 alloy thin films were obtained at the wide current density range from 5 A/dm2 to 100 A/dm2. SiO2 content in deposits was ca. 10 % at the maximum using the solution containing a surfactant with molecular weight range of 200 to 300.15th International Conference on Thin Films, ICTF 2011; Kyoto; Japan; 8 November 2011 ~ 11 November 201
Higher Derivative Corrections to Eleven Dimensional Supergravity via Local Supersymmetry
In this paper we derive higher derivative corrections to the eleven
dimensional supergravity by applying the Noether method with respect to the N=1
local supersymmetry. An ansatz for the higher derivative effective action,
which includes quartic terms of the Riemann tensor, is parametrized by 132
parameters. Then we show that by the requirement of the local supersymmetry,
the higher derivative effective action is essentially described by two
parameters. The bosonic parts of these two superinvariants completely match
with the known results obtained by the perturbative calculations in the type
IIA superstring theory. Since the calculations are long and systematic, we
build the computer programming to check the cancellation of the variations
under the local supersymmetry. This is an extended version of our previous
paper hep-th/0508204.Comment: 67 pages, no figure, references added, typos correcte
Self-consistency and Symmetry in d-dimensions
Bethe approximation is shown to violate Bravais lattices translational
invariance. A new scheme is then presented which goes over the one-site Weiss
model yet preserving initial lattice symmetry. A mapping to a one-dimensional
finite closed chain in an external field is obtained. Lattice topology
determines the chain size. Using recent results in percolation, lattice
connectivity between chains is argued to be where is the
coordination number and is the space dimension. A new self-consistent
mean-field equation of state is derived. Critical temperatures are thus
calculated for a large variety of lattices and dimensions. Results are within a
few percent of exact estimates. Moreover onset of phase transitions is found to
occur in the range . For the Ising hypercube it yields the Golden
number limit .Comment: 16 pages, latex, Phys. Rev. B (in press
Chameleonic dilaton, nonequivalent frames, and the cosmological constant problem in quantum string theory
The chameleonic behaviour of the String theory dilaton is suggested. Some of
the possible consequences of the chameleonic string dilaton are analyzed in
detail. In particular, (1) we suggest a new stringy solution to the
cosmological constant problem and (2) we point out the non-equivalence of
different conformal frames at the quantum level. In order to obtain these
results, we start taking into account the (strong coupling) string loop
expansion in the string frame (S-frame), therefore the so-called form factors
are present in the effective action. The correct Dark Energy scale is recovered
in the Einstein frame (E-frame) without unnatural fine-tunings and this result
is robust against all quantum corrections, granted that we assume a proper
structure of the S-frame form factors in the strong coupling regime. At this
stage, the possibility still exists that a certain amount of fine-tuning may be
required to satisfy some phenomenological constraints. Moreover in the E-frame,
in our proposal, all the interactions are switched off on cosmological length
scales (i.e. the theory is IR-free), while higher derivative gravitational
terms might be present locally (on short distances) and it remains to be seen
whether these facts clash with phenomenology. A detailed phenomenological
analysis is definitely necessary to clarify these points
Long-Time Behavior of Velocity Autocorrelation Function for Interacting Particles in a Two-Dimensional Disordered System
The long-time behavior of the velocity autocorrelation function (VACF) is
investigated by the molecular dynamics simulation of a two-dimensional system
which has both a many-body interaction and a random potential. With
strengthening the random potential by increasing the density of impurities, a
crossover behavior of the VACF is observed from a positive tail, which is
proportional to t^{-1}, to a negative tail, proportional to -t^{-2}. The latter
tail exists even when the density of particles is the same order as the density
of impurities. The behavior of the VACF in a nonequilibrium steady state is
also studied. In the linear response regime the behavior is similar to that in
the equilibrium state, whereas it changes drastically in the nonlinear response
regime.Comment: 12 pages, 5 figure
Finite Action in d5 Gauged Supergravity and Dilatonic Conformal Anomaly for Dual Quantum Field Theory
Gauged supergravity (SG) with single scalar (dilaton) and arbitrary scalar
potential is considered. Such dilatonic gravity describes special RG flows in
extended SG where scalars lie in one-dimensional submanifold of total space.
The surface counterterm and finite action for such gauged SG in three-, four-
and five-dimensional asymptotically AdS space are derived. Using finite action
and consistent gravitational stress tensor (local surface counterterm
prescription) the regularized expressions for free energy, entropy and mass of
d4 dilatonic AdS black hole are found. The same calculation is done within
standard reference background subtraction.
The dilaton-dependent conformal anomaly from d3 and d5 gauged SGs is
calculated using AdS/CFT correspondence. Such anomaly should correspond to two-
and four-dimensional dual quantum field theory which is classically (not
exactly) conformally invariant, respectively. The candidate c-functions from d3
and d5 SGs are suggested. These c-functions which have fixed points in
asymptoticaly AdS region are expressed in terms of dilatonic potential and they
are positively defined and monotonic for number of potentials.Comment: LaTeX file, 46 pages, two appendixes and some clarifications are
adde
Brane-World and Holography
We consider the brane-world in the holographic point of view. Bearing the
realistic models in mind, the bulk massless scalar field is introduced. First
of all, we find the constraint on the coupling of the scalar fields with the
matter(not holographic CFT) on the brane. We show that the traceless part of
the energy-momentum tensor of holographic CFT is a part of the bulk Weyl
tensor. The trace part which comes from the trace-anomaly is corresponding to
the -term appeared in the generalized FRW equation in the brane-world.Comment: 4 pages, minor change
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