16,518 research outputs found
Comment on "Constant stress and pressure rheology of colloidal suspensions"
This is a comment on the recent letter by Wang and Brady on "Constant stress
and pressure rheology of colloidal suspensions", Phys. Rev. Lett. 115, 158301
(2015).Comment: 1 page; under review -> v2: publishe
Topological Field Theories and Geometry of Batalin-Vilkovisky Algebras
The algebraic and geometric structures of deformations are analyzed
concerning topological field theories of Schwarz type by means of the
Batalin-Vilkovisky formalism. Deformations of the Chern-Simons-BF theory in
three dimensions induces the Courant algebroid structure on the target space as
a sigma model. Deformations of BF theories in dimensions are also analyzed.
Two dimensional deformed BF theory induces the Poisson structure and three
dimensional deformed BF theory induces the Courant algebroid structure on the
target space as a sigma model. The deformations of BF theories in
dimensions induce the structures of Batalin-Vilkovisky algebras on the target
space.Comment: 25 page
Graphical Classification of Global SO(n) Invariants and Independent General Invariants
This paper treats some basic points in general relativity and in its
perturbative analysis. Firstly a systematic classification of global SO(n)
invariants, which appear in the weak-field expansion of n-dimensional
gravitational theories, is presented. Through the analysis, we explain the
following points: a) a graphical representation is introduced to express
invariants clearly; b) every graph of invariants is specified by a set of
indices; c) a number, called weight, is assigned to each invariant. It
expresses the symmetry with respect to the suffix-permutation within an
invariant. Interesting relations among the weights of invariants are given.
Those relations show the consistency and the completeness of the present
classification; d) some reduction procedures are introduced in graphs for the
purpose of classifying them. Secondly the above result is applied to the proof
of the independence of general invariants with the mass-dimension for the
general geometry in a general space dimension. We take a graphical
representation for general invariants too. Finally all relations depending on
each space-dimension are systematically obtained for 2, 4 and 6 dimensions.Comment: LaTex, epsf, 60 pages, many figure
AKSZ-BV Formalism and Courant Algebroid-induced Topological Field Theories
We give a detailed exposition of the Alexandrov-Kontsevich-Schwarz-
Zaboronsky superfield formalism using the language of graded manifolds. As a
main illustarting example, to every Courant algebroid structure we associate
canonically a three-dimensional topological sigma-model. Using the AKSZ
formalism, we construct the Batalin-Vilkovisky master action for the model.Comment: 13 pages, based on lectures at Rencontres mathematiques de Glanon
200
Vortex-lattice melting in two-dimensional superconductors in intermediate fields
To examine the field dependence of the vortex lattice melting transition in
two-dimensional (2D) superconductors, Monte Carlo simulations of the 2D
Ginzburg-Landau (GL) model are performed by extending the conventional lowest
Landau level (LL) approximation to include several {\it higher} LL modes of the
superconducting order parameter with LL indices up to six. It is found that a
nearly vertical melting line in lower fields, which is familiar within the
elastic theory, is reached just by including higher LL modes with LL indices
less than five, and that the first order character of the melting transition in
higher fields is significantly weakened with decreasing the field.
Nevertheless, a genuine crossover to the consecutive continuous melting picture
intervened by a hexatic liquid is not found within the use of the GL model.Comment: 6 pages, 7 figures. To appear in Phys. Rev.
QP-Structures of Degree 3 and 4D Topological Field Theory
A A BV algebra and a QP-structure of degree 3 is formulated. A QP-structure
of degree 3 gives rise to Lie algebroids up to homotopy and its algebraic and
geometric structure is analyzed. A new algebroid is constructed, which derives
a new topological field theory in 4 dimensions by the AKSZ construction.Comment: 17 pages, Some errors and typos have been correcte
Effect of in-plane line defects on field-tuned superconductor-insulator transition behavior in homogeneous thin film
Field-tuned superconductor-insulator transition (FSIT) behavior in 2D
isotropic and homogeneous thin films is usually accompanied by a nonvanishing
critical resistance at low . It is shown that, in a 2D film including line
defects paralle to each other but with random positions perpendicular to them,
the (apparent) critical resistance in low limit vanishes, as in the 1D
quantum superconducting (SC) transition, under a current parallel to the line
defects. This 1D-like critical resistive behavior is more clearly seen in
systems with weaker point disorder and may be useful in clarifying whether the
true origin of FSIT behavior in the parent superconductor is the glass
fluctuation or the quantum SC fluctuation. As a by-product of the present
calculation, it is also pointed out that, in 2D films with line-like defects
with a long but {\it finite} correlation length parallel to the lines, a
quantum metallic behavior intervening the insulating and SC ones appears in the
resistivity curves.Comment: 16 pages, 14 figure
Mode-Coupling Theory as a Mean-Field Description of the Glass Transition
Mode-coupling theory (MCT) is conjectured to be a mean-field description of
dynamics of the structural glass transition and the replica theory to be its
thermodynamic counterpart. However, the relationship between the two theories
remains controversial and quantitative comparison is lacking. In this Letter,
we investigate MCT for monatomic hard sphere fluids at arbitrary dimensions
above three and compare the results with replica theory. We find grave
discrepancies between the predictions of two theories. While MCT describes the
nonergodic parameter quantitatively better than the replica theory in three
dimension, it predicts a completely different dimension dependence of the
dynamical transition point. We find it to be due to the pathological behavior
of the nonergodic parameters derived from MCT, which exhibit negative tails in
real space at high dimensions.Comment: 5 pages, to appear in Phys. Rev. Lett.: Typos have been correcte
Thermodynamics and Structural Properties of the High Density Gaussian Core Model
We numerically study thermodynamic and structural properties of the
one-component Gaussian core model (GCM) at very high densities. The solid-fluid
phase boundary is carefully determined. We find that the density dependence of
both the freezing and melting temperatures obey the asymptotic relation, , , where is the number density, which
is consistent with Stillinger's conjecture. Thermodynamic quantities such as
the energy and pressure and the structural functions such as the static
structure factor are also investigated in the fluid phase for a wide range of
temperature above the phase boundary. We compare the numerical results with the
prediction of the liquid theory with the random phase approximation (RPA). At
high temperatures, the results are in almost perfect agreement with RPA for a
wide range of density, as it has been already shown in the previous studies. In
the low temperature regime close to the phase boundary line, although RPA fails
to describe the structure factors and the radial distribution functions at the
length scales of the interparticle distance, it successfully predicts their
behaviors at shorter length scales. RPA also predicts thermodynamic quantities
such as the energy, pressure, and the temperature at which the thermal
expansion coefficient becomes negative, almost perfectly. Striking ability of
RPA to predict thermodynamic quantities even at high densities and low
temperatures is understood in terms of the decoupling of the length scales
which dictate thermodynamic quantities from the interparticle distance which
dominates the peak structures of the static structure factor due to the
softness of the Gaussian core potential.Comment: 10 pages, 10 figure
Theoretical Description of Nearly Discontinuous Transition in Superconductors with Paramagnetic Depairing
Based on a theoretical argument and Monte Carlo simulations of a
Ginzburg-Landau model derived microscopically, it is argued that, in type-II
superconductors where {\it both} the paramagnetic {\it and} orbital depairings
are important, a strong first-order transition (FOT) at expected in
the mean field (MF) approximation never occurs in real systems and changes due
to the fluctuation into a crossover. The present result explains why a {\it
nearly} discontinuous crossover at with {\it no} intrinsic hysteresis
is observed only in a clean superconducting material with a singlet pairing and
a high condensation energy such as CeCoIn.Comment: Publication version. See cond-mat/0306060 regarding a corresponding
long pape
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