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Manuscript Title: FlowPy - a numerical solver for functional renormalization group equations
Authors: Thomas Fischbacher, Franziska Synatschke-Czerwonka
Program title: FlowPy
Catalogue identifier: AEPB_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 184(2013)1931
Programming language: Python, C.
Computer: PC or workstation.
Operating system: Unix.
RAM: approx. 40 MB
Keywords: Functional Renormalization Group Equations, Momentum dependent flow equations.
PACS: 11.10.Gh, 11.10.Hi.
Classification: 4.12, 11.1.

External routines: Python, libpython, SciPy, NumPy, python-simpleparse.

Nature of problem:
In the study of functional renormalization group equations non-local integro-differential equations arise which furthermore can contain singular coefficient functions for the highest derivative and may only be given implicitly. Solving these equations beyond the simplest cases thus provides a numerical challenge.

Solution method:
A combination of numerical differentiation, integration, interpolation, and ODE solving.

Due to the nature of FRG problems, computational effort (run time) will scale quadratically with the number of discretization points. Using more than at most a few hundred discretization points may be impractical.

Running time:
For the SUSY_QM example: ~ 10 seconds for 10 support points, ~ 5 minutes for 100 discretization points. For the momentum_dependent_wavefunction example: ~ 40 minutes for 5 discretization points.