arXiv subjects

Margarita Garcia Perez

Publications and source records attributed to Margarita Garcia Perez.

39 records · Page 3Linked to original sources

arXiv1994

Sphalerons and Other Saddles from Cooling

We describe a new cooling algorithm for SU(2) lattice gauge theory. It has any critical point of the energy or action functional as a fixed point. In particular, any number of unstable modes may occur. We also provide insight in the convergence of the cooling algorithms. A number of solutions will be discussed, in particular the sphalerons for twisted and periodic boundary conditions which are important for the low-energy dynamics of gauge theories. For a unit cubic volume we find a sphaleron energy of resp. $\cE_s=34.148(2)$ and $\cE_s=72.605(2)$ for the twisted and periodic case. Remarkably, the magnetic field for the periodic sphaleron satisfies at all points $\Tr B_x^2=\Tr B_y^2=\Tr B_z^2$.

hep-lat↗

arXiv1993

From Perturbation Theory to Confinement: How the String Tension is built up

We study the spatial volume dependence of electric flux energies for SU(2) Yang-Mills fields on the torus with twisted boundary conditions. The results approach smoothly the rotational invariant Confinement regime. The would-be string tension is very close to the infinite volume result already for volumes of $(1.2 \ {\rm fm.})^3$. We speculate on the consequences of our result for the Confinement mechanism.

hep-lat↗

arXiv1993

Instantons from over-improved cooling

Lattice artefacts are used, through modified lattice actions, as a tool to find the largest instantons in a toroidal geometry [0,L]^3X[0,T] for T to infinity. It is conjectured that the largest instanton is associated with tunnelling through a sphaleron. Existence of instantons with at least 8 parameters can be proven with the help of twisted boundary conditions in the time direction. Numerical results for SU(2) gauge theory obtained by cooling are presented to demonstrate the viability of the method.

hep-lat↗