Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2609.11570

How much chaos can be generated by gravitational collapse before reaching the Planck scale?

David Brizuela·Sara F. Uria·Edward Wilson-Ewing
View original source ↗Read source document ↗Export metadata ↓

Abstract

According to the Belinski-Khalatnikov-Lifshitz (BKL) conjecture the dynamics of general relativity near singularities is highly chaotic. However, since general relativity breaks down at singularities, it is generally expected that a more fundamental theory, such as quantum gravity, is needed to describe the spacetime dynamics in regions with large spacetime curvature. In the absence of a widely accepted theory of quantum gravity, it remains unclear how exactly quantum effects may modify the classical evolution. Taking a conservative point of view, in this paper we study the classical dynamics of a gravitational collapse, starting from a strong-field (though classical) scenario up to the Planck scale to quantify how much chaos is generated during the time the Einstein equations can be trusted. Specifically, we use the Shannon entropy and Kullback-Leibler divergence, as well as Fourier analysis, to find that, when the Planck scale is reached, the chaotic features of the model remain relatively underdeveloped. This suggests that, at least during the classical regime, chaos is not strong enough to erase all information about the initial state of the universe, or about a previous classical universe in the context of bouncing cosmologies. In addition, we also characterize the final invariant phase-space distribution for the chaotic Bianchi IX dynamics in general relativity, which provides a novel description of its invariant repeller.

Explore related subjects

gr-qc

Keep this discovery

BibTeXRIS

David Brizuela, Sara F. Uria, Edward Wilson-Ewing. 2026-09-10. How much chaos can be generated by gravitational collapse before reaching the Planck scale?. https://arxiv.org/abs/2609.11570

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Electrovacuum Black Hole Uniqueness

We prove the black hole uniqueness conjecture in the axially symmetric, stationary, electrovacuum setting, subject to the refined asymptotic analysis of the associated singular harmonic maps, which includes an analyticity hypothesis at the axes. More precisely, it is shown that any asymptotically flat solution of the Einstein--Maxwell equations in this class, with more than one black hole horizon component is either: Majumdar--Papapetrou, up to a duality rotation, in which case all logarithmic angle defects vanish, or every finite axis rod logarithmic angle defect is strictly negative and hence every interaction force is strictly attractive. The proof extends the singular harmonic map method used for vacuum Kerr uniqueness in [18].

gr-qc↗
arXiv2026

Constraining Modified Mass-to-Horizon Cosmology Through Primordial Inflationary Observables

We investigate slow-roll inflation in a modified cosmological framework inspired by a generalized mass-to-horizon relation (MHR), $M=\gamma {c^2 L^n}/{G}$, where $n$ is a real parameter and $\gamma$ a dimensional constant. Using Padmanabhan's emergence paradigm, we derive the modified Friedmann equations for a flat FRW universe and analyze the dynamics of a canonical scalar field (inflaton) under the slow-roll approximation. We study the resulting inflationary phenomenology for power-law and Starobinsky potentials. For power-law potentials, the MHR modification fails to reconcile these models with current CMB constraints on $r$ and $n_s$. In contrast, Starobinsky inflation exhibits significant sensitivity to deviations from $n=1$. A perturbative analysis ($n=1+\Delta$) yields corrections to inflationary observables. We observe that the scalar power-spectrum normalization, under a fixed-Starobinsky prescription, imposes the stringent constraint $0.960 \lesssim n \lesssim 1.040$ for $N=60$ efolds. This is considerably tighter than spectral-index bounds. Our results establish inflation, particularly Starobinsky-like models, as a sensitive probe of generalized horizon thermodynamics and departures from standard MHR scaling.

gr-qc↗
arXiv2026

Improving the Sensitivity of Gravitational Wave Detection with Weighted Conformal Prediction

In the last decade, kilometre-scale interferometric gravitational-wave detectors have observed hundreds of compact binary mergers, the majority of which are binary black holes. However, the data are noise-dominated, and multiple independent search algorithms (pipelines) are used to enhance sensitivity and improve robustness. Rather than the standard approach of selecting the most significant pipeline output, we combine the outputs from all pipelines using a conformal prediction-based framework to provide statistically rigorous confidence estimates for candidate events. While combining pipelines improves sensitivity and ranking robustness, it requires a principled statistical framework that remains valid as data properties evolve across observing runs. A key challenge is distribution shifts between simulated datasets used for training and calibration and the real, unlabelled, observations used for testing, which can invalidate coverage guarantees and bias confidence estimates. In this work, we address this challenge by incorporating likelihood-ratio reweighting into our conformal prediction framework to account for covariate shift. Using mock datasets containing simulated signals, we demonstrate that weighted conformal prediction restores well-calibrated coverage under covariate shift and increases the confidence of events near the detection threshold, recovering true signals that would otherwise be missed.

gr-qc↗