1,076 research outputs found
Thermofield Dynamics of the Heterotic String - Physical Aspects of the Thermal Duality -
The thermofield dynamics of the D = 10 heterotic thermal string theory is
described in proper reference to the thermal duality symmetry as well as the
thermal stability of modular invariance in association with the global phase
structure of the D = 10 heterotic thermal string ensemble.Comment: 8 pages, LaTeX, Minor correction
Thermal -Brane Boundary States from Green-Schwarz Superstrings
In this paper we thermalize the type II superstrings in the GS formulation by
applying the TFD formalism. The thermal boundary conditions on the thermal
Hilbert space are obtained from the BPS -brane boundary conditions at zero
temperature. We show that thermal boundary states can be obtained by
thermalization from the BPS -branes at zero temperature. These new states
can be interpreted as thermal -branes. Next, we discuss the supersymmetry
breaking of the thermal string in the TFD approach. We identify the broken
supersymmetry with the -transformation while the
-transformation is preserved. Also, we compute the thermal partition
function and the entropy of the thermal string.Comment: 23 pages, LATeX fil
First Order Semiclassical Thermal String in the AdS Spacetime
We formulate the finite temperature theory for the free thermal excitations
of the bosonic string in the anti-de Sitter (AdS) spacetime in the Thermo Field
Dynamics (TFD) approach. The spacetime metric is treated exactly while the
string and the thermal reservoir are semiclassically quantized at the first
order perturbation theory with respect to the dimensionless parameter \epsilon
= \a ' H^{-2}. In the conformal black-hole AdS background the
quantization is exact. The method can be extended to the arbitrary AdS
spacetime only in the first order perturbation. This approximation is taken in
the center of mass reference frame and it is justified by the fact that at the
first order the string dynamics is determined only by the interaction between
the {\em free} string oscillation modes and the {\em exact} background. The
first order thermal string is obtained by thermalization of the system
carried on by the TFD Bogoliubov operator. We determine the free thermal string
states and compute the local entropy and free energy in the center of mass
reference frame.Comment: Minor typos corrected. Two references added. LATeX file, 19 page
Time-dependent perturbation theory for vibrational energy relaxation and dephasing in peptides and proteins
Without invoking the Markov approximation, we derive formulas for vibrational
energy relaxation (VER) and dephasing for an anharmonic system oscillator using
a time-dependent perturbation theory. The system-bath Hamiltonian contains more
than the third order coupling terms since we take a normal mode picture as a
zeroth order approximation. When we invoke the Markov approximation, our theory
reduces to the Maradudin-Fein formula which is used to describe VER properties
of glass and proteins. When the system anharmonicity and the renormalization
effect due to the environment vanishes, our formulas reduce to those derived by
Mikami and Okazaki invoking the path-integral influence functional method [J.
Chem. Phys. 121 (2004) 10052]. We apply our formulas to VER of the amide I mode
of a small amino-acide like molecule, N-methylacetamide, in heavy water.Comment: 16 pages, 5 figures, 5 tables, submitted to J. Chem. Phy
Are Americans more Altruistic than the Japanese Comparison of Saving and Bequest Motives.
In this paper, we analyze a variety of data on saving motives, bequest motives, and bequest division from the "Comparative Survey of Savings in Japan and the United States", a binational survey conducted in 1996 by the Institute for Posts and Telecommunications Policy of the Ministry of Posts and Telecommunications of the Government of Japan, in order to shed light on which model of household behavior applies in the two countries.HOUSEHOLD ; SAVINGS ; CONSUMPTION
Onsager-Machlup action-based path sampling and its combination with replica exchange for diffusive and multiple pathways
For sampling multiple pathways in a rugged energy landscape, we propose a
novel action-based path sampling method using the Onsager-Machlup action
functional. Inspired by the Fourier-path integral simulation of a quantum
mechanical system, a path in Cartesian space is transformed into that in
Fourier space, and an overdamped Langevin equation is derived for the Fourier
components to achieve a canonical ensemble of the path at a finite temperature.
To avoid "path trapping" around an initially guessed path, the path sampling
method is further combined with a powerful sampling technique, the replica
exchange method. The principle and algorithm of our method is numerically
demonstrated for a model two-dimensional system with a bifurcated potential
landscape. The results are compared with those of conventional transition path
sampling and the equilibrium theory, and the error due to path discretization
is also discussed.Comment: 20 pages, 5 figures, submitted to J. Chem. Phy
Entanglement induced by nonadiabatic chaos
We investigate entanglement between electronic and nuclear degrees of freedom
for a model nonadiabatic system. We find that entanglement (measured by the von
Neumann entropy of the subsystem for the eigenstates) is large in a statistical
sense when the system shows ``nonadiabatic chaos'' behavior which was found in
our previous work [Phys. Rev. E {\bf 63}, 066221 (2001)]. We also discuss
non-statistical behavior of the eigenstates for the regular cases.Comment: 4 pages, 6 figures, submitted to Phys. Rev.
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