11,998 research outputs found
A Feynman graph selection tool in GRACE system
We present a Feynman graph selection tool {\tt grcsel}, which is an
interpreter written in C language. In the framework of {\tt GRACE}, it enables
us to get a subset of Feynman graphs according to given conditions.Comment: 3 pages, 2 figures, Latex, ACAT200
Berry Curvature on the Fermi Surface: Anomalous Hall Effect as a Topological Fermi-Liquid Property
The intrinsic anomalous Hall effect in metallic ferromagnets is shown to be
controlled by Berry phases accumulated by adiabatic motion of quasiparticles on
the Fermi surface, and is purely a Fermi-liquid property, not a ``bulk'' Fermi
sea property like Landau diamagnetism, as has been previously supposed. Berry
phases are a new topological ingredient that must be added to Landau
Fermi-liquid theory in the presence of broken inversion or time-reversal
symmetry.Comment: 4 pages, 0 figures; to appear in Physical Review Letters; cleaner
form of main formula+note added confirming continued validity of result in
interacting Fermi liquids: + improved summary paragraph stating result; final
published version (minor changes
Geometrical Construction of Heterogeneous Loop Amplitudes in 2D Gravity
We study a disk amplitude which has a complicated heterogeneous matter
configuration on the boundary in a system of the (3,4) conformal matter coupled
to two-dimensional gravity. It is analyzed using the two-matrix chain model in
the large N limit. We show that the disk amplitude calculated by
Schwinger-Dyson equations can completely be reproduced through purely
geometrical consideration. From this result, we speculate that all
heterogeneous loop amplitudes can be derived from the geometrical consideration
and the consistency among relevant amplitudes.Comment: 13 pages, 11 figure
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