ACAT 2011

Session

Tuesday 06th - Computations in Theoretical Physics

6 Sept 2011, 14:00

7. HYPERDIRE: HYPERgeometric DIfferential REduction HYPERDIRE: HYPERgeometric DIfferential REduction Mathematica based programs for differential reduction of hypergeometric functions and its application to Feynman Diagrams Calculation.

Dr Bytev Vladimir (JINR)

06/09/2011, 14:00

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

The differential reduction algorithm allows to change the values of parameters of any Horn-type hypergeometric functions on arbitrary integers numbers. The description of mathematical part of algorithm have been presented on ACAT08 by M.Kalmykov [6]. We will describe the status of project and will present a new version of MATHEMATICA based package including a several important...

2. DRA method: Powerful tool for the calculation of the loop integrals.

Dr Roman Lee (Budker Institute of Nuclear Physics)

06/09/2011, 14:25

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

The method of calculation of the loop integrals based on the dimensional recurrence relation and analyticity of the integrals as functions of $d$ is reviewed. Special emphasis is made on the possibility to automatize many steps of the method. New results obtained with this method are presented.

113. Reduze 2

Dr Cedric Studerus (University of Bielefeld)

06/09/2011, 14:50

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

Reduze is a computer program for reducing Feynman Integrals to master integrals employing the Gauss/Laporta algorithm. Reduze is written in C++ and uses the GiNaC library to perform simplifications of the algebraic prefactors in the system of equations. In this talk, the new version, Reduze 2, is presented. The program supports fully parallelised computations with MPI and allows to resume...

111. Polynomial Algebra in Form 4

Jan Kuipers (Nikhef)

06/09/2011, 15:15

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

New features of the symbolic algebra package Form 4 are discussed. Most importantly, these features include polynomial factorization and polynomial GCD computation. Examples of their use are shown. One of them is an exact version of Mincer which gives answers in terms of rational polynomials and 5 master integrals.

107. Status of parallelization of FORM

Takahiro Ueda (Karlsruhe Institute of Technology)

06/09/2011, 16:10

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

We report on the current status of the development of parallel versions of the symbolic manipulation system FORM. Currently there are two parallel versions of the FORM: one is TFORM which is based on the POSIX threads and for running on multicore machines, and the other is ParFORM which uses the MPI and can run on computer clusters. By using these versions, most of existing FORM programs...

70. Reweighting NNPDFs.

Mr Francesco Cerutti (Universitat de Barcelona)

06/09/2011, 16:35

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

I present a method, elaborated within the NNPDF Collaboration, that allows the inclusion of the information contained in new datasets into an existing set of parton distribution functions without the need for refitting. The method exploits bayesian inference in the space of PDF replicas, computing for each replica a chisquare with respect to the new dataset and a weight associated to this. ...

76. Self-Organizing Maps Parametrization of Deep Inelastic Structure Functions with Error Determination

Prof. simonetta liuti (university of virginia)

06/09/2011, 17:00

Track 3: Computations in Theoretical Physics - Techniques and Methods

Parallel talk

We will present a method to extract parton distribution functions from hard scattering processes based on an alternative type of neural networks, the Self-Organizing Maps (SOMs). Quantitative results including a detailed treatment of uncertainties will be presented within a Next to Leading Order analysis of both unpolarized and polarized inclusive deep inelastic scattering data. With a fully...