Divergences in open quantum systems
Here, we show that for cubic scalar field theories in five and more spacetime dimensions, and for the T = 0 limit of the CaldeiraLeggett model, the quantum master equation for longwavelength modes initially unentangled from shortdistance modes, and at second order in perturbation theory, contains divergences in the nonHamiltonian terms. These divergences ensure that the equations of motion for expectation values of composite operators closes on expectation values of renormalized operators. Along the way we show that initial “jolt” singularities which occur in the equations of motion for operators linear in the fundamental variables persist for quadratic operators, and are removed if one chooses an initial state projected onto low energies, following the BornOppenheimer approximation.
 Authors:

^{[1]};
^{[2]}
 Brandeis Univ., Waltham, MA (United States). Martin Fisher School of Physics; Univ. of California, Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics; State Univ. of New York (SUNY), Plattsburgh, NY (United States). C.N. Yang Inst. for Theoretical Physics
 Brandeis Univ., Waltham, MA (United States). Martin Fisher School of Physics
 Publication Date:
 Grant/Contract Number:
 SC0009987
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of High Energy Physics (Online)
 Additional Journal Information:
 Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2018; Journal Issue: 4; Journal ID: ISSN 10298479
 Publisher:
 Springer Berlin
 Research Org:
 Brandeis Univ., Waltham, MA (United States)
 Sponsoring Org:
 USDOE Office of Science (SC)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Effective Field Theories; Quantum Dissipative Systems; Renormalization Group
 OSTI Identifier:
 1503319
Agón, Cesar, and Lawrence, Albion. Divergences in open quantum systems. United States: N. p.,
Web. doi:10.1007/jhep04(2018)008.
Agón, Cesar, & Lawrence, Albion. Divergences in open quantum systems. United States. doi:10.1007/jhep04(2018)008.
Agón, Cesar, and Lawrence, Albion. 2018.
"Divergences in open quantum systems". United States.
doi:10.1007/jhep04(2018)008. https://www.osti.gov/servlets/purl/1503319.
@article{osti_1503319,
title = {Divergences in open quantum systems},
author = {Agón, Cesar and Lawrence, Albion},
abstractNote = {Here, we show that for cubic scalar field theories in five and more spacetime dimensions, and for the T = 0 limit of the CaldeiraLeggett model, the quantum master equation for longwavelength modes initially unentangled from shortdistance modes, and at second order in perturbation theory, contains divergences in the nonHamiltonian terms. These divergences ensure that the equations of motion for expectation values of composite operators closes on expectation values of renormalized operators. Along the way we show that initial “jolt” singularities which occur in the equations of motion for operators linear in the fundamental variables persist for quadratic operators, and are removed if one chooses an initial state projected onto low energies, following the BornOppenheimer approximation.},
doi = {10.1007/jhep04(2018)008},
journal = {Journal of High Energy Physics (Online)},
number = 4,
volume = 2018,
place = {United States},
year = {2018},
month = {4}
}