Perturbation theory for the logarithm of a positive operator by Nima Lashkari, Hong Liu, Srivatsan Rajagopal

“…Often, one encounters the situation where the operator under consideration, which we denote by ∆, can be related by a perturbative series to another operator ∆0, whose logarithm is known. We set up a perturbation theory for the logarithm log ∆. It turns out that the terms in the series possess a remarkable algebraic structure, which enables us to write them in the form of nested commutators plus some “contact terms”.…”
Get full text

Perturbation Theory Near Degenerate Exceptional Points by Miloslav Znojil

Subjects: Get full text

Black hole perturbation theory and multiple polylogarithms by Gleb Aminov, Paolo Arnaudo, Giulio Bonelli, Alba Grassi, Alessandro Tanzini

“…Abstract We study black hole linear perturbation theory in a four-dimensional Schwarzschild (anti) de Sitter background. …”
Get full text

On electric fields in hot QCD: perturbation theory by G. Endrődi, G. Markó

“…Abstract We investigate the response of a hot gas of quarks to external electric fields via leading-order perturbation theory. In particular, we discuss how equilibrium is maintained in the presence of the electric field and calculate the electric susceptibility, providing its high-temperature expansion for arbitrary quark mass. …”
Get full text

Amplitude/operator basis in chiral perturbation theory by Ian Low, Jing Shu, Ming-Lei Xiao, Yu-Hui Zheng

“…Abstract We establish a systematic construction of the on-shell amplitude/operator basis for Chiral Perturbation Theory (ChPT) in D = 4 spacetime dimensions and with an arbitrary number of flavors N f . …”
Get full text

S-duality invariant perturbation theory improved by holography by Abhishek Chowdhury, Masazumi Honda, Somyadip Thakur

“…The interpolating functions are consistent with previous results on the perturbation theory, holographic computation and full S-duality. …”
Get full text

The basis and application of perturbation theory to neutron diffusion by Lewins, Jeffery

Get full text

Broadcasting on Trees Near Criticality: Perturbation Theory by Yu, Qian, Polyanskiy, Yury

Get full text

Perturbation theory for the logarithm of a positive operator by Lashkari, Nima, Liu, Hong, Rajagopal, Srivatsan

“…Often, one encounters the situation where the operator under consideration, which we denote by ∆, can be related by a perturbative series to another operator ∆0, whose logarithm is known. We set up a perturbation theory for the logarithm log ∆. It turns out that the terms in the series possess a remarkable algebraic structure, which enables us to write them in the form of nested commutators plus some “contact terms”.…”
Get full text

Perturbation theory in Lemaitre-Tolman-Bondi cosmology by Clarkson, C, Clifton, T, February, S

Configuration–Interaction Perturbation Theory Calculations of Pu II by Igor Savukov

Subjects: “…configuration-interaction perturbation theory…”
Get full text

Local infrared safety in time-ordered perturbation theory by George Sterman, Aniruddha Venkata

“…We go on to show that it is possible to eliminate unphysical singularities that appear in time-ordered perturbation theory for arbitrary amplitudes. This is done by reorganizing TOPT into an equivalent form that combines classes of time orderings into a “partially time-ordered perturbation theory”. …”
Get full text

Universality in the Exact Renormalization Group: Comparison to Perturbation Theory by José Gaite

Get full text

Generalized Perturbation Theory for Weakly Deformed Microdisk Cavities by Xuenan Zhang, Bin Liu, Xue Zhou, Xin Yan, Fang Wang, Zongfu Yu, Tonglei Cheng

Subjects: Get full text

First-order perturbation theory of eigenmodes for systems with interfaces by Z. Sztranyovszky, W. Langbein, E. A. Muljarov

“…We present an exact first-order perturbation theory for eigenmodes in systems with interfaces causing material discontinuities. …”
Get full text

Functional Epistemology “Nullifies” Dyson’s Rebuttal of Perturbation Theory by Karl Svozil

Get full text

Off-Shell Duality Invariance of Schwarzschild Perturbation Theory by Adam R. Solomon

Subjects: “…black hole perturbation theory…”
Get full text

Unifying semiclassics and quantum perturbation theory at nonlinear order by Daniel Kaplan, Tobias Holder, Binghai Yan

“…Focusing on the second order nonlinear response, here we show how the semiclassical limit can be recovered from perturbation theory in the velocity gauge, provided that finite quasiparticle lifetimes are taken into account. …”
Get full text

Chiral perturbation theory of the hyperfine splitting in (muonic) hydrogen by Franziska Hagelstein, Vadim Lensky, Vladimir Pascalutsa

“…Here we perform a first calculation based on the baryon chiral perturbation theory (B $$\chi $$ χ PT). At leading orders it provides a prediction for the proton polarizability effects in hydrogen (H) and muonic hydrogen ( $$\mu $$ μ H). …”
Get full text

Complex analysis of divergent perturbation theory at finite temperature by Sun, Y, Burton, H

“…We investigate the convergence properties of finite-temperature perturbation theory by considering the mathematical structure of thermodynamic potentials using complex analysis. …”