222 research outputs found
Small Thermal Fluctuation on a Large Domain
Weak first-order phase transitions proceed with percolation of new phase. The
kinematics of this process is clarified from the point of view of subcritical
bubbles. We examine the effect of small subcritical bubbles around a large
domain of asymmetric phase by introducing an effective geometry. The
percolation process can be understood as a perpetual growth of the large domain
aided by the small subcritical bubbles.Comment: 6 pages, latex, to be published in Progress of Theoretical Physic
Physics of quantum measurement and its interdisciplinary applications
Quantum dynamics of the collective mode and individual particles on a ring is
studied as the simplest model of projective quantum measurement. In this model,
the collective mode measures an individual single quantum system. The heart of
the model is the wide separation of time scales which yields the distinction of
classical and quantum degrees of freedom beyond the standard Gross-Pitaevskii
equation. In some restricted cases we derive the Born probability rule. This
model is the quantum mechanics version of the effective action method in
quantum field theory, which describes the origin of the primordial density
fluctuation as classical variables. It turns out that the classical version of
this same model successfully describes the dynamics of geomagnetic variation
including the polarity flips over 160 million years. The essence of this
description is again the coexistence of the wide separated time scales.Comment: 8 pages, 6 figure
Quantum Subcritical Bubbles
We quantize subcritical bubbles which are formed in the weakly first order
phase transition. We find that the typical size of the thermal fluctuation
reduces in the quantum-statistical physics. We estimate the typical size and
the amplitude of thermal fluctuations near the critical temperature in the
electroweak phase transition using quantum statistical average. Furthermore
based on our study, we give implication on the dynamics of phase transition.Comment: Latex file, 9pp, to be published in Progress of Theoretical Physic
On the Power Spectrum Density of Gamma Ray Bursts
Gamma ray bursts (GRBs) are known to have short-time variability and
power-law behavior with the index -1.67 in the power spectrum density.
Reanalyzing the expanded data, we have found a) the power-law comes from the
global profile of the burst and not from the self-similar shots nor rapid
fluctuations in the luminosity profile. b) The power indices vary from burst to
burst and the value -1.67 is given simply as the mean value of the
distribution; there is no systematic correlation among GRBs to yield the power
law.Comment: 10 pages, 4 figures, submitted to ApJ Letter
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