#perturbation theory

topicperturbation theory

10 papers · 1 filter

astro-ph.CO2026

GGI Lectures on Large-Scale Structure Perturbation Theory (Effective Field Theory)

Mikhail M. Ivanov

These lecture notes introduce non-linear perturbation theory and effective field theory methods for modeling the large-scale distribution of galaxies, targeting undergraduate and e…

gr-qc2026

Nonlinear Dynamics near the Threshold of Gravitational Collapse

Jaime Redondo-Yuste, Josu C. Aurrekoetxea

The authors use numerical relativity simulations of a self‑gravitating scalar field to compare perturbative expansions around flat spacetime with full nonlinear dynamics, identifyi…

hep-th2026

Quantum Fisher information of the Klein--Gordon, , and Dirac vacua

Preslav Asenov, Alessio Serafini

The paper computes the quantum Fisher information of vacuum states for Klein‑Gordon, φ⁴, and Dirac quantum field theories as a function of the mass parameter in various spacetime d…

gr-qc2026

Analytic backreaction of a scalar wig on a Schwarzschild black hole

Marco de Cesare, Manuel Del Piano, Carlos A. R. Herdeiro

The paper analytically computes how a massive scalar quasi‑bound state backreacts on a Schwarzschild black hole, deriving metric perturbations, horizon evolution, and the scalar’s…

quant-ph2026

Robustness of periodicity in Grover walks under a magnetic vector potential

Hiroto Sekido, Etsuo Segawa

The paper investigates how adding a magnetic vector potential affects the periodic behavior of Grover quantum walks on finite graphs, deriving conditions for robustness and showing…

math.OC2026

Norm-Cone Conjugation and Fenchel-Type Duality Beyond Convexity

Fernando García-Castaño, Miguel Ángel Melguizo-Padial

The paper proposes a norm‑cone conjugation framework that extends Fenchel‑type duality to nonconvex functions, defines a corresponding subdifferential, and builds a perturbation du…