Results 31 to 40 of about 396 (66)

gTybalt - a free computer algebra system [PDF]

open access: yes, 2003
This article documents the free computer algebra system "gTybalt". The program is build on top of other packages, among others GiNaC, TeXmacs and Root.
Weinzierl, Stefan
core   +1 more source

A streamlined difference ring theory: Indefinite nested sums, the alternating sign and the parameterized telescoping problem

open access: yes, 2015
We present an algebraic framework to represent indefinite nested sums over hypergeometric expressions in difference rings. In order to accomplish this task, parts of Karr's difference field theory have been extended to a ring theory in which also the ...
Schneider, Carsten
core   +1 more source

Special functions, transcendentals and their numerics [PDF]

open access: yes, 2017
Cyclotomic polylogarithms are reviewed and new results concerning the special constants that occur are presented.
Ablinger, Jakob   +3 more
core   +2 more sources

The Two-mass Contribution to the Three-Loop Gluonic Operator Matrix Element $A_{gg,Q}^{(3)}$ [PDF]

open access: yes, 2018
We calculate the two-mass QCD contributions to the massive operator matrix element $A_{gg,Q}$ at $\mathcal{O} (\alpha_s^3)$ in analytic form in Mellin $N$- and $z$-space, maintaining the complete dependence on the heavy quark mass ratio.
Ablinger, J.   +5 more
core   +4 more sources

Symbolic and Numerical Analysis in General Relativity with Open Source Computer Algebra Systems

open access: yes, 2018
We study three computer algebra systems, namely SageMath (with SageManifolds package), Maxima (with ctensor package) and Python language (with GraviPy module), which allow tensor manipulation for general relativity calculations along with general ...
Birkandan, Tolga   +3 more
core   +1 more source

General $\varepsilon$-representation for scalar one-loop Feynman integrals

open access: yes, 2015
A systematic study of the scalar one-loop two-, three-, and four-point Feynman integrals is performed. We consider all cases of mass assignment and external invariants and derive closed expressions in arbitrary space-time dimension in terms of higher ...
Bluemlein, Johannes   +2 more
core   +1 more source

Calculation of Massless Feynman Integrals using Harmonic Sums [PDF]

open access: yes, 2006
A method for the evaluation of the epsilon expansion of multi-loop massless Feynman integrals is introduced. This method is based on the Gegenbauer polynomial technique and the expansion of the Gamma function in terms of harmonic sums. Algorithms for the
Bekavac, Stefan
core   +1 more source

Random Sampling in Computational Algebra: Helly Numbers and Violator Spaces [PDF]

open access: yes, 2015
This paper transfers a randomized algorithm, originally used in geometric optimization, to computational problems in commutative algebra. We show that Clarkson's sampling algorithm can be applied to two problems in computational algebra: solving large ...
De Loera, Jesús A.   +2 more
core   +3 more sources

Automated Generation of Non-Linear Loop Invariants Utilizing Hypergeometric Sequences

open access: yes, 2017
Analyzing and reasoning about safety properties of software systems becomes an especially challenging task for programs with complex flow and, in particular, with loops or recursion.
Humenberger, Andreas   +2 more
core   +1 more source

Calculating Three Loop Ladder and V-Topologies for Massive Operator Matrix Elements by Computer Algebra

open access: yes, 2015
Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable $N$ and the ...
Ablinger, J.   +5 more
core   +1 more source

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