${\rm QED}_{\rm M}$ $U_1$ background field generator

C/C++ code to generate electro-quenched U1 fields for LQCD.
Original author: Michael G. Endres.
Porting to new repo: Ben Hoerz and Andre Walker-Loud

• Installation
• Debugging
• Acknowledgements
• Copyright Notice

NOTE: we are working on an upgrade that will use cmake and enable command line choices for input parameters, such as the lattice volume, photon mass, etc.

Installation

1) To create the library edit the FFTWLIB flag in the files:

scripts/compile/make_lib.sh
and
scripts/compile/make_bin.sh
to point to where your FFTW library is located.

Note that these files (along with scripts/compile/make_clean.sh) are my lazy alternative to using a Makefile; they will be used to compile the library and test/production programs.

2) Next run:

./scripts/compile/make_lib.sh

This should create the library file called noncompact_u1.a (as well as an obj directory containing some *.o files which were created during the comilation)

3) To compile one of the test programs, ENTER the test program directory, e.g.,

cd tests/gauge_invariance/
and then run the script:
../../scripts/compile/make_bin.sh main.C
This will create your new binary called a.out

4 To run the test program, type:

./a.out

5) Production code is compiled and run similarly to test code

Debugging

====DEBUGGING AND MEMORY USE====

A useful tool for detecting memory leaks/use and profiling is valgrind (no recompilation of your code is required!):

http://valgrind.org/

Some of the tools included are:

1) To profile memory use, run:

valgrind --tool=massif ./a.out

2) To detect memory leaks, access of unallocated memory locations, etc.,, run:

valgrind --leak-check=yes ./a.out

3) Profiling can be done with

valgrind --tool=callgrind ./a.out
callgrind_annotate [options] callgrind.out.<pid>

Acknowledgements

If you use this code, please cite

Massive photons: an infrared regularization scheme for lattice QCD+QED
M. G. Endres, A. Shindler, B. C. Tiburzi, A. Walker-Loud
Phys.Rev.Lett. 117 (2016) 7, 072002 [arXiv:1507.08916]

Copyright Notice

noncompact_u1 (qed_m) Copyright (c) 2022, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from the U.S. Dept. of Energy) and Massachusetts Institute of Technology (MIT). All rights reserved.

If you have questions about your rights to use or distribute this software, please contact Berkeley Lab's Intellectual Property Office at IPO@lbl.gov.

NOTICE. This Software was developed under funding from the U.S. Department of Energy and the U.S. Government consequently retains certain rights. As such, the U.S. Government has been granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the Software to reproduce, distribute copies to the public, prepare derivative works, and perform publicly and display publicly, and to permit others to do so.