234 research outputs found
Computing periods of rational integrals
A period of a rational integral is the result of integrating, with respect to
one or several variables, a rational function over a closed path. This work
focuses particularly on periods depending on a parameter: in this case the
period under consideration satisfies a linear differential equation, the
Picard-Fuchs equation. I give a reduction algorithm that extends the
Griffiths-Dwork reduction and apply it to the computation of Picard-Fuchs
equations. The resulting algorithm is elementary and has been successfully
applied to problems that were previously out of reach.Comment: To appear in Math. comp. Supplementary material at
http://pierre.lairez.fr/supp/periods
Computing topological zeta functions of groups, algebras, and modules, II
Building on our previous work (arXiv:1405.5711), we develop the first
practical algorithm for computing topological zeta functions of nilpotent
groups, non-associative algebras, and modules. While we previously depended
upon non-degeneracy assumptions, the theory developed here allows us to
overcome these restrictions in various interesting cases.Comment: 33 pages; sequel to arXiv:1405.571
Two-loop Integral Reduction from Elliptic and Hyperelliptic Curves
We show that for a class of two-loop diagrams, the on-shell part of the
integration-by-parts (IBP) relations correspond to exact meromorphic one-forms
on algebraic curves. Since it is easy to find such exact meromorphic one-forms
from algebraic geometry, this idea provides a new highly efficient algorithm
for integral reduction. We demonstrate the power of this method via several
complicated two-loop diagrams with internal massive legs. No explicit elliptic
or hyperelliptic integral computation is needed for our method.Comment: minor changes: more references adde
Standard model plethystics
We study the vacuum geometry prescribed by the gauge invariant operators of the minimal supersymmetric standard model via the plethystic program. This is achieved by using several tricks to perform the highly computationally challenging Molien-Weyl integral, from which we extract the Hilbert series, encoding the invariants of the geometry at all degrees. The fully refined Hilbert series is presented as the explicit sum of 1422 rational functions. We found a good choice of weights to unrefine the Hilbert series into a rational function of a single variable, from which we can read off the dimension and the degree of the vacuum moduli space of the minimal supersymmetric standard model gauge invariants. All data in Mathematica format are also presented
Groebner.jl: A package for Gr\"obner bases computations in Julia
We introduce the Julia package Groebner.jl for computing Gr\"obner bases with
the F4 algorithm. Groebner.jl is an efficient, lightweight, portable,
thoroughly tested, and documented open-source software. The package works over
integers modulo a prime and over the rationals and supports various monomial
orderings. The implementation incorporates modern symbolic computation
techniques and leverages the Julia type system and tooling, which allows
Groebner.jl to be on par in performance with the leading computer algebra
systems. Our package is freely available at
https://github.com/sumiya11/Groebner.jl .Comment: 10 page
A verified Common Lisp implementation of Buchberger's algorithm in ACL2
In this article, we present the formal verification of a Common
Lisp implementation of Buchberger's algorithm for computing
Gröbner bases of polynomial ideals. This work is carried out in
ACL2, a system which provides an integrated environment where
programming (in a pure functional subset of Common Lisp) and
formal verification of programs, with the assistance of a theorem
prover, are possible. Our implementation is written in a real
programming language and it is directly executable within the
ACL2 system or any compliant Common Lisp system. We provide
here snippets of real verified code, discuss the formalization details
in depth, and present quantitative data about the proof effort
Explicit formula for the generating series of diagonal 3D rook paths
Let denote the number of ways in which a chess rook can move from a
corner cell to the opposite corner cell of an
three-dimensional chessboard, assuming that the piece moves closer to the goal
cell at each step. We describe the computer-driven \emph{discovery and proof}
of the fact that the generating series admits
the following explicit expression in terms of a Gaussian hypergeometric
function: G(x) = 1 + 6 \cdot \int_0^x \frac{\,\pFq21{1/3}{2/3}{2} {\frac{27
w(2-3w)}{(1-4w)^3}}}{(1-4w)(1-64w)} \, dw.Comment: To appear in "S\'eminaire Lotharingien de Combinatoire
A Computer Algebra System for R: Macaulay2 and the m2r Package
Algebraic methods have a long history in statistics. Apart from the ubiquitous applications of linear algebra, the most visible manifestations of modern algebra in statistics are found in the young field of algebraic statistics, which brings tools from commutative algebra and algebraic geometry to bear on statistical problems. Now over two decades old, algebraic statistics has applications in a wide range of theoretical and applied statistical domains. Nevertheless, algebraic statistical methods are still not mainstream, mostly due to a lack of easy off-the-shelf implementations. In this article we debut m2r, an R package that connects R to Macaulay2 through a persistent back-end socket connection running locally or on a cloud server. Topics range from basic use of m2r to applications and design philosophy
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