21,691 research outputs found
Noncommutative/Nonlinear BPS Equations without Zero Slope Limit
It is widely believed that via the Seiberg-Witten map, the linearly realized
BPS equation in the non-commutative space is related to the non-linearly
realized BPS equation in the commutative space in the zero slope limit. We show
that the relation also holds without taking the zero slope limit as is expected
from the arguments of the BPS equation for the non-Abelian Born-Infeld theory.
This is regarded as an evidence for the relation between the two BPS equations.
As a byproduct of our analysis, the non-linear instanton equation is solved
exactly.Comment: 9 pages, LaTeX, no figures, v2: discussion on the string tension
removed, v3: minor modification
A new method of joint nonparametric estimation of probability density and its support
In this paper we propose a new method of joint nonparametric estimation of
probability density and its support. As is well known, nonparametric kernel
density estimator has "boundary bias problem" when the support of the
population density is not the whole real line. To avoid the unknown boundary
effects, our estimator detects the boundary, and eliminates the boundary-bias
of the estimator simultaneously. Moreover, we refer an extension to a simple
multivariate case, and propose an improved estimator free from the unknown
boundary bias
Superconformal Chern-Simons Partition Functions of Affine D-type Quiver from Fermi Gas
We consider the partition function of the superconformal Chern-Simons
theories with the quiver diagram being the affine D-type Dynkin diagram.
Rewriting the partition function into that of a Fermi gas system, we show that
the perturbative expansions in 1/N are summed up to an Airy function, as in the
ABJM theory or more generally the theories of the affine A-type quiver. As a
corollary, this provides a proof for the previous proposal in the large N
limit. For special values of the Chern-Simons levels, we further identify three
species of the membrane instantons and also conjecture an exact expression of
the overall constant, which corresponds to the constant map in the topological
string theory.Comment: 23 pages, 4 figures; v2: section 4.2 added, one figure adde
Descent Relation of Tachyon Condensation from Boundary String Field Theory
We analyze how lower-dimensional bosonic D-branes further decay, using the
boundary string field theory. Especially we find that the effective tachyon
potential of the lower-dimensional D-brane has the same profile as that of
D25-brane.Comment: 10 pages, LaTeX, 1 figure, v2: reference added, v3: typos corrected
and text improve
A new kernel estimator of hazard ratio and its asymptotic mean squared error
The hazard function is a ratio of a density and survival function, and it is
a basic tool of the survival analysis. In this paper we propose a kernel
estimator of the hazard ratio function, which are based on a modification of
\'{C}wik and Mielniczuk's method. We study nonparametric estimators of the
hazard function and compare those estimators by means of asymptotic mean
squared error (). We obtain asymptotic bias and variance of the new
estimator, and compare them with a naive estimator. The asymptotic variance of
the new estimator is always smaller than the naive estimator's, so we also
discuss an improvement of using Terrell and Scott's bias reduction
method. The new modified estimator ensures the non-negativity, and we
demonstrate the numerical improvement
Instanton Effects in Orientifold ABJM Theory
We investigate another supersymmetric Chern-Simons theory called the
orientifold ABJM theory, which replaces the unitary supergroup structure of the
ABJM theory with an orthosymplectic one. Its non-perturbative structure is
completely clarified by considering the duplication of the quiver.Comment: 21 pages, 1 figure, v2: a reference added, minor changes, v3: typos
corrected, published versio
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