Results 11 to 20 of about 7,625,136 (322)
Screened perturbation theory [PDF]
Physics Letters B, 1997 Talk presented at Eotvos Conference in Science - 1997, Strong and Electroweak Matter '97, 21-25 May 1997, Eger, Hungary, 5 pages, LaTeX, 2 ...
Karsch, Frithjof +2 more
openaire +4 more sources
D-instanton perturbation theory
Journal of High Energy Physics, 2020 D-instanton world-volume theory has open string zero modes describing collective coordinates of the instanton. The usual perturbative amplitudes in the D-instanton background suffer from infra-red divergences due to the presence of these zero modes, and ...
Ashoke Sen
doaj +1 more source
Phonons and related crystal properties from density-functional perturbation theory [PDF]
, 2000 This article reviews the current status of lattice-dynamical calculations in crystals, using density-functional perturbation theory, with emphasis on the plane-wave pseudopotential method.
S. Baroni +3 more
semanticscholar +1 more source
Journal of Chemical Physics, 1992 K. Andersson, P. Malmqvist, B. Roos
semanticscholar +3 more sources
European Physical Journal C: Particles and Fields, 2020 Integral equations for meson–baryon scattering amplitudes are obtained by utilizing time-ordered perturbation theory for a manifestly Lorentz-invariant formulation of baryon chiral perturbation theory.
X.-L. Ren +3 more
doaj +1 more source
Chiral perturbation theory for GR
Journal of High Energy Physics, 2020 We describe a new perturbation theory for General Relativity, with the chiral first-order Einstein-Cartan action as the starting point. Our main result is a new gauge-fixing procedure that eliminates the connection-to-connection propagator.
Kirill Krasnov, Yuri Shtanov
doaj +1 more source
Chiral Perturbation Theory [PDF]
Annual Review of Nuclear and Particle Science, 2007 This review gives a brief introduction to chiral perturbation theory in its various settings. We discuss some applications of recent interest, including chiral extrapolations for lattice gauge theory.
Bernard, Véronique, Meißner, Ulf-G.
openaire +2 more sources
The perturbation theory of matrix mechanics based on its canonical transformations
Results in Physics, 2022 We elucidate that the canonical transformations of matrix mechanics are just the transformations of different representations of the standard quantum mechanics, reproduce the non-degenerate, degenerate and time-dependent perturbation theory in three men ...
Yong-Yi Huang
doaj +1 more source
Many-body perturbation theory calculations using the yambo code [PDF]
Journal of Physics: Condensed Matter, 2019 yambo is an open source project aimed at studying excited state properties of condensed matter systems from first principles using many-body methods. As input, yambo requires ground state electronic structure data as computed by density functional theory
D. Sangalli +19 more
semanticscholar +1 more source
First-order Perturbation Theory for Eigenvalues and Eigenvectors [PDF]
SIAM Review, 2019 We present first-order perturbation analysis of a simple eigenvalue and the corresponding right and left eigenvectors of a general square matrix, not assumed to be Hermitian or normal.
A. Greenbaum, Ren-Cang Li, M. Overton
semanticscholar +1 more source