Calculation of Polarizabilities for Atoms with Open Shells by Vladimir Dzuba

“…A version of the configuration interaction method for atoms with open shells (the Configuration Interaction with Perturbation Theory—CIPT method, PRA 95, 012503 (2017)) is extended for calculation of static and dynamic polarizabilities. …”
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Ab initio Vibration-Rotation Spectroscopy by Walter Thiel

“…It addresses the computation of anharmonic force fields and spectroscopic constants in the context of rovibrational perturbation theory as well as variational calculations of vibrational levels, on the basis of highly accurate ab initio potential energy surfaces. …”
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Classical statistical simulation of quantum field theory by Takayuki Hirayama

“…Abstract We propose a procedure of computing the n-point function in perturbation theory of the quantum field theory as the average over the complex Gaussian noises in a classical theory. …”
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Casimir–Lifshitz interaction between dielectric heterostructures by Azari, A, Samanta, H, Golestanian, R

“…The interaction between arbitrary dielectric heterostructures is studied within the framework of a recently developed dielectric contrast perturbation theory. It is shown that periodically patterned dielectric or metallic structures lead to oscillatory lateral Casimir-Lifshitz forces, as well as modulations in the normal force as they are displaced with respect to one another. …”

Morphogen gradient from a noisy source. by England, J, Cardy, J

“…We investigate the effect of time-dependent noise on the shape of a morphogen gradient in a developing embryo. Perturbation theory is used to calculate the deviations from deterministic behavior in a simple reaction-diffusion model of robust gradient formation, and the results are confirmed by numerical simulation. …”

Small-χ structure functions and heavy flavour production by Catani, S, Ciafaloni, M, Hautmann, F

“…The use of the kt-factorization theorem to compute high energy cross sections in resummed perturbation theory is reviewed. The results for heavy flavour photoproduction at small χ are discussed in detail. …”

The heavy-ion spin-orbit interaction by Brink, D, Sukumar, C

“…An expression for the induced spin-orbit potential in a heavy-ion collision is derived by making an adiabatic approximation to the effective interaction in second-order perturbation theory. An explicit form for the induced spin-orbit interaction for the case of a projectile of arbitrary ground state spin S is given and is shown to be equivalent to the result obtained using the methods of geometrical magnetism. © 1999 Elsevier Science B.V.…”

REGGEON CALCULUS DERIVED FROM EIKONAL MODEL by Cardy, J

“…A reggeon calculus is derived from a hybrid perturbation-theory model using eikonal techniques. The resulting reggeon coupling functions have a simple form which enables many diagrams of interest to be evaluated explicitly. …”

CRITICAL EXPONENTS OF REGGEON FIELD-THEORY by Cardy, J

“…By using the method of Lipatov to determine the behavior of perturbation theory at large order, we derive a convergent numerical procedure for the calculation of the critical exponents of Reggeon field theory, based on the loop expansion and the ε{lunate} expansion. …”

Asteroseismic Signature of a Large Active Region by Emanuele Papini, Laurent Gizon, Laurent Gizon

“…However linear perturbation theory provides useful guidance to search for the observational signature of large individual active regions in stellar oscillation power spectra.…”
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Numerical methods of resonant dynamics for the Galaxy by Donner, R, Donner, Ralf

“…We derive generating functions for first-order perturbation theory and the associated orbital frequencies by matrix calculus. …”

Galaxy bias in the era of LSST: perturbative bias expansions by Nicola, A, Hadzhiyska, B, Findlay, N, García-García, C, Alonso, D, Slosar, A, Guo, Z, Kokron, N, Angulo, R, Aviles, A, Blazek, J, Dunkley, J, Jain, B, Pellejero, M, Sullivan, J, Walter, CW, Zennaro, M

“…Specifically, we compare two perturbative approaches, Lagrangian perturbation theory (LPT) and Eulerian perturbation theory (EPT) to two variants of Hybrid Effective Field Theory (HEFT), with our fiducial implementation of these models including terms up to second order in the bias expansion as well as nonlocal bias and deviations from Poissonian stochasticity. …”

G0W0 plus BSE calculations of quasiparticle band structure and optical properties of nitrogen-doped antimony trisulfide for near infrared optoelectronic and solar cells application... by Lawal, Abdullahi, Shaari, A., Taura, L. S., Radzwan, Afiq, Idris, M. C., Madugu, M. L.

“…Many-body perturbation theory (MBPT) based on the G0W0 approximation is used for the quasiparticle (QP) band structure. …”

Feynman integrals for binary systems of black holes by Philipp Alexander Kreer, Robert Runkel, Stefan Weinzierl

“…The initial phase of the inspiral process of a binary black-hole system can be described by perturbation theory. At the third post-Minkowskian order a two-loop double box graph, known as H-graph, contributes. …”
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Comparison Study between Quantum Electrodynamics theory (QED) and Quantum Chromodynamics theory (QCD) by Salman AL-chatouri, Mohey-Aldin Nizam, Silva AL-khassi

“… In this study we calculated the correlation coefficient to solve the Klein_Gordan equation and the Dirac equation in quantum electrodynamics theory, applying timed pendent perturbation theory. The calculations show correlation coefficient are coupled in the amount and this consistent with previously known results,  we conducted a comparison between Quantum Electrodynamics theory (QED) and Quantum Chromodynamics theory (QCD), we noticed that it was agreed and the differences between two theory are through charge screening in QED and QCD.   …”
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Unbiased elimination of negative weights in Monte Carlo samples by Jeppe R. Andersen, Andreas Maier

“…We demonstrate the overall performance and systematic improvement with increasing event sample size, based on predictions for the production of a W boson with two jets calculated at next-to-leading order perturbation theory.…”
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Existence of Traveling Wave Fronts for a Generalized Nonlinear Schrodinger Equation by Yuanhua Lin, Liping He

“…By using the geometric singular perturbation theory, the existence of traveling wave fronts is proved. …”
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Comparison Study between Quantum Electrodynamics theory (QED) and Quantum Chromodynamics theory (QCD) by سلمان الشاتوري, محي الدين نظام, سيلفا الخصي

“… In this study we calculated the correlation coefficient to solve the Klein_Gordan equation and the Dirac equation in quantum electrodynamics theory, applying timed pendent perturbation theory. The calculations show correlation coefficient are coupled in the amount and this consistent with previously known results,  we conducted a comparison between Quantum Electrodynamics theory (QED) and Quantum Chromodynamics theory (QCD), we noticed that it was agreed and the differences between two theory are through charge screening in QED and QCD.   …”
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Supersymmetric gauge theories in twistor space by Boels, R, Mason, L, Skinner, D

“…We construct a twistor space action for ≤ 4 super Yang-Mills theory and show that it is equivalent to its four dimensional spacetime counterpart at the level of perturbation theory. We compare our partition function to the original twistor-string proposal, showing that although our theory is closely related to string theory, it is free from conformal supergravity. …”

Diffractive deeply inelastic scattering of hadronic states with small transverse size by Hautmann, F, Kunszt, Z, Soper, D

“…If the transverse size of the hadronic state is sufficiently small, these distributions are calculable using perturbation theory. We present such a calculation and discuss the underlying dynamics. …”