gf_update kernel broken? (Unit Test #326)

Added by Christopher Pinke almost 7 years ago. Updated almost 7 years ago.

Status:Done Start date:22 Oct 2012
Priority:High Due date:
Assignee:Christopher Pinke % Done:


Target version:- Estimated time:1.00 hour


At cdf48d884ad7aa9d3bd068382ee0ec00af45b296, gf_update tests 2 and 5 fail, indicating that the kernel is not working correctly!

Related issues

blocks CL2QCD - Unit Test #325: test opencl_module_hmc Done 22 Oct 2012


Updated by Christopher Pinke almost 7 years ago

  • Status changed from New to In Progress

Updated by Christopher Pinke almost 7 years ago

With comit:15edbeaadf01ce6961528d336ab64cb6c5e24c93 I worked over the gf_update tests. The kernel was not broken.

I was confused that when updating a cold gf with a cold input gm, the plaquette stayed "1", but the polyakov loop changed. However, in this case one can simply calculate the results of the update.
The plaquette stays the same because the updated links are all the same matrix (exp(i eps * cold ae) -> Pl ~ tr(1) because of the daggered links ), while the polyakov loop (who does not contain daggered links) becomes exp(i eps * cold ae * Ntau) at every spatial position. And this is not a unit matrix, thus the polyakovloop is not one anymore. One can check that by doubling Ntau and halfing eps, which then gives the same value of the polyakov loop.

  • Estimated time set to 1.00
  • % Done changed from 0 to 100
  • Status changed from In Progress to Done

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