Pith. sign in

REVIEW 8 cited by

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2209.01929 v2 pith:YCUU57HR submitted 2022-09-05 hep-th astro-ph.COgr-qchep-ph

Benchmarking the cosmological master equations

classification hep-th astro-ph.COgr-qchep-ph
keywords masterbackgroundenvironmentequationequationsfieldsystemthey
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

Master equations are commonly employed in cosmology to model the effect of additional degrees of freedom, treated as an "environment", onto a given "system". However, they rely on assumptions that are not necessarily satisfied in cosmology, where the environment may be out of equilibrium and the background is dynamical. In this work, we apply the master-equation program to a model that is exactly solvable, and which consists of two linearly coupled scalar fields evolving on a cosmological background. The light field plays the role of the system and the heavy field is the environment. By comparing the exact solution to the output of the master equation, we can critically assess its performance. We find that the master equation exhibits a set of "spurious" terms that explicitly depend on the initial conditions, and which arise as a consequence of working on a dynamical background. Although they cancel out in the perturbative limit of the theory (i.e. at leading orders in the interaction strength), they spoil resummation. However, when those terms are removed, the master equation performs impressively well to reproduce the power spectra and the amount of the decoherence of the light field, even in the strongly decohered regime. We conclude that master equations are able to perform late-time resummation, even though the system is far from the Markovian limit, provided spurious contributions are suppressed.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 8 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Quantum Stochastic Inflation

    hep-th 2026-06 unverdicted novelty 8.0

    Stochastic inflation emerges as GKLS open-system dynamics from tracing entangled modes entering a coarse-grained de Sitter patch, reproducing the classical phase-space Fokker-Planck equation.

  2. Hidden quantum-informatic symmetries of quasi-de Sitter backgrounds

    hep-th 2026-07 unverdicted novelty 7.0

    Wands-dual quasi-de Sitter backgrounds produce identical symplectic eigenvalues in the Gaussian covariance matrix of localized scalar modes, revealing a quantum-informatic symmetry preserved by the duality's canonical...

  3. Stochastic inflation from a non-equilibrium renormalization group

    hep-th 2026-05 unverdicted novelty 7.0

    A generalized Fokker-Planck equation for stochastic inflation is derived from a Polchinski-type renormalization group flow on the density matrix, incorporating dissipative and diffusive corrections beyond the leading order.

  4. Schwinger-Keldysh Path Integral for Gauge theories

    hep-th 2026-04 unverdicted novelty 7.0

    Constructs a manifestly diagonal-BRST-invariant Schwinger-Keldysh path integral for open non-Abelian gauge theories with arbitrary physical initial states, yielding Ward-Takahashi-Slavnov-Taylor identities and a Keldy...

  5. When the Environment Speaks: Quantum Signatures in Non-Attractor Inflation

    astro-ph.CO 2026-07 conditional novelty 6.0

    An open quantum system treatment of curvature perturbations during Ultra-Slow-Roll inflation shows that environmental decoherence erases the interference dip, modifies the growth slope, and induces oscillatory feature...

  6. Schwinger-Keldysh Path Integral for Gauge theories

    hep-th 2026-04 unverdicted novelty 6.0

    A manifestly BRST-invariant Schwinger-Keldysh path integral is derived for non-Abelian gauge theories with generic initial states, enabling perturbative Ward-Takahashi-Slavnov-Taylor identities and Open EFT expansions...

  7. Gauging Open EFTs from the top down

    hep-th 2025-12 unverdicted novelty 6.0

    Derives gauge-invariant influence functionals for photons and Stueckelberg fields in open U(1) gauge EFTs via BRST on the in-in contour after integrating out matter.

  8. Directly computing Wigner functions for open quantum systems

    quant-ph 2025-12 unverdicted novelty 6.0

    An expression is derived to compute time-dependent Wigner functions directly from initial values in open quantum systems of a non-relativistic particle with a general environment.