scholarly journals Aspects of renormalization in finite-density field theory

2015 ◽  
Vol 91 (19) ◽  
Author(s):  
A. Liam Fitzpatrick ◽  
Gonzalo Torroba ◽  
Huajia Wang
Keyword(s):  
Field Theory ◽  
Density Field ◽  
Finite Density

scholarly journals Aspects of quantum information in finite density field theory

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Lucas Daguerre ◽  
Raimel Medina ◽  
Mario Solís ◽  
Gonzalo Torroba
Keyword(s):  
Field Theory ◽  
Quantum Information ◽  
Mutual Information ◽  
Fermi Surface ◽  
Relative Entropy ◽  
Chemical Potential ◽  
Operator Product ◽  
Dirac Fermions ◽  
Long Distance ◽  
Finite Density

Abstract We study different aspects of quantum field theory at finite density using methods from quantum information theory. For simplicity we focus on massive Dirac fermions with nonzero chemical potential, and work in 1 + 1 space-time dimensions. Using the entanglement entropy on an interval, we construct an entropic c-function that is finite. Unlike what happens in Lorentz-invariant theories, this c-function exhibits a strong violation of monotonicity; it also encodes the creation of long-range entanglement from the Fermi surface. Motivated by previous works on lattice models, we next calculate numerically the Renyi entropies and find Friedel-type oscillations; these are understood in terms of a defect operator product expansion. Furthermore, we consider the mutual information as a measure of correlation functions between different regions. Using a long-distance expansion previously developed by Cardy, we argue that the mutual information detects Fermi surface correlations already at leading order in the expansion. We also analyze the relative entropy and its Renyi generalizations in order to distinguish states with different charge and/or mass. In particular, we show that states in different superselection sectors give rise to a super-extensive behavior in the relative entropy. Finally, we discuss possible extensions to interacting theories, and argue for the relevance of some of these measures for probing non-Fermi liquids.

scholarly journals SURPRISES IN NONPERTURBATIVE DYNAMICS IN σ-MODEL AT FINITE DENSITY

2004 ◽  
Vol 19 (18) ◽  
pp. 1341-1356 ◽  
Author(s):  
V. P. GUSYNIN ◽  
V. A. MIRANSKY ◽  
I. A. SHOVKOVY
Keyword(s):  
Elementary Particle ◽  
Field Theory ◽  
Quantum Field Theory ◽  
Particle Physics ◽  
Chemical Potential ◽  
High Density ◽  
Quantum Field ◽  
Finite Density ◽  
Elementary Particle Physics ◽  
Kaon Condensate

The linear SU (2)L× SU (2)R σ-model occupies a unique place in elementary particle physics and quantum field theory. It has been recently realized that when a chemical potential for hypercharge is added, it becomes a toy model for the description of the dynamics of the kaon condensate in high density QCD. We review recent results in nonperturbative dynamics obtained in the ungauged and gauged versions of this model.

scholarly journals Effective Field Theory and Finite-Density Systems

2008 ◽  
Vol 58 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Richard J. Furnstahl ◽  
Gautam Rupak ◽  
Thomas Schäfer
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Effective Field ◽  
Finite Density
Sign in / Sign up

Export Citation Format

Share Document