12,110 research outputs found
Stochastic Analysis of Gaussian Processes via Fredholm Representation
We show that every separable Gaussian process with integrable variance
function admits a Fredholm representation with respect to a Brownian motion. We
extend the Fredholm representation to a transfer principle and develop
stochastic analysis by using it. We show the convenience of the Fredholm
representation by giving applications to equivalence in law, bridges, series
expansions, stochastic differential equations and maximum likelihood
estimations
Semi-classical trace formulas and heat expansions
in the recent paper [Journal of Physics A, 43474-0288 (2011)], B. Helffer and
R. Purice compute the second term of a semi-classical trace formula for a
Schr\"odinger operator with magnetic field. We show how to recover their
formula by using the methods developped by the geometers in the seventies for
the heat expansions.Comment: To appear in "Analysis of Partial Differential Equations
An excursion from enumerative goemetry to solving systems of polynomial equations with Macaulay 2
Solving a system of polynomial equations is a ubiquitous problem in the
applications of mathematics. Until recently, it has been hopeless to find
explicit solutions to such systems, and mathematics has instead developed deep
and powerful theories about the solutions to polynomial equations. Enumerative
Geometry is concerned with counting the number of solutions when the
polynomials come from a geometric situation and Intersection Theory gives
methods to accomplish the enumeration.
We use Macaulay 2 to investigate some problems from enumerative geometry,
illustrating some applications of symbolic computation to this important
problem of solving systems of polynomial equations. Besides enumerating
solutions to the resulting polynomial systems, which include overdetermined,
deficient, and improper systems, we address the important question of real
solutions to these geometric problems.
The text contains evaluated Macaulay 2 code to illuminate the discussion.
This is a chapter in the forthcoming book "Computations in Algebraic Geometry
with Macaulay 2", edited by D. Eisenbud, D. Grayson, M. Stillman, and B.
Sturmfels. While this chapter is largely expository, the results in the last
section concerning lines tangent to quadrics are new.Comment: LaTeX 2e, 22 pages, 1 .eps figure. Source file (.tar.gz) includes
Macaulay 2 code in article, as well as Macaulay 2 package realroots.m2
Macaulay 2 available at http://www.math.uiuc.edu/Macaulay2 Revised with
improved exposition, references updated, Macaulay 2 code rewritten and
commente
Discrete logarithms in curves over finite fields
A survey on algorithms for computing discrete logarithms in Jacobians of
curves over finite fields
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