Results 31 to 40 of about 683,210 (331)
Physical Review X, 2021 Thanks to the nearsightedness principle, the low-energy electronic structure of solids can be represented by localized states such as the Wannier functions.
Jae-Mo Lihm, Cheol-Hwan Park
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Perturbation theory in nonstandard cosmology [PDF]
, 2019 We study inhomogeneous perturbations away from the strongly homogeneous background cosmology previously studied. The problem is greatly simplified by using the mapping on the inner Schwarzschild solution.
Scharf, Günter
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PERTURBATIVE QUANTUM FIELD THEORY [PDF]
Challenges for the 21st Century, 2001 This talk introduces perturbative quantum field on a heuristic level. It is directed at an audience familiar with elements of quantum mechanics, but not necessarily with high energy physics. It includes a discussion of the strategies behind experimental tests of fundamental theories, and of the field theory interpretations of these tests.
openaire +3 more sources
Closed form bound-state perturbation theory
International Journal of Mathematics and Mathematical Sciences, 1980 The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the
Ollie J. Rose, Carl G. Adler
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Massive renormalization scheme and perturbation theory at finite temperature
Physics Letters B, 2015 We argue that the choice of an appropriate, massive, renormalization scheme can greatly improve the apparent convergence of perturbation theory at finite temperature.
Jean-Paul Blaizot, Nicolás Wschebor
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Cosmological perturbation theory
, 2004 This is a review on cosmological perturbation theory. After an introduction, it presents the problem of gauge transformation. Gauge invariant variables are introduced and the Einstein and conservation equations are written in terms of these variables ...
R. Durrer, T. Kanazawa, V. F. Mukhanov
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Lattice regularized chiral perturbation theory [PDF]
, 2003 Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed.
Borasoy, Bugra +2 more
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Long Wavelength Coherency in Well Connected Electric Power Networks
IEEE Access, 2022 We investigate coherent oscillations in large scale transmission power grids, where large groups of generators respond in unison to a distant disturbance. Such long wavelength coherent phenomena are known as inter-area oscillations.
Julian Fritzsch, Philippe Jacquod
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Implementing Unitarity in Perturbation Theory [PDF]
, 2001 Unitarity cannot be perserved order by order in ordinary perturbation theory because the constraint $UU^\dagger=\1$ is nonlinear. However, the corresponding constraint for $K=\ln U$, being $K=-K^\dagger$, is linear so it can be maintained in every order ...
A. B. Migdal +28 more
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Density-functional perturbation theory goes time-dependent
Atti della Accademia Peloritana dei Pericolanti : Classe di Scienze Fisiche, Matematiche e Naturali, 2008 The scope of time-dependent density-functional theory (TDDFT) is limited to the lowest portion of the spectrum of rather small systems (a few tens of atoms at most).
Gebauer, Ralph +2 more
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