Rotation overcharges vectorized black holes

A charged black hole has a ceiling: extremality bounds the charge that a given mass and spin can support. Vector hair has so far only lowered it. In the Einstein--Maxwell--Vector (EMV) model, where a massless vector field couples nonminimally to the electromagnetic invariant, the spherically symmetric vectorized Reissner--Nordström black holes are strictly undercharged: vector hair is paid for in charge. Whether this ceiling is a property of the vector field or merely of spherical symmetry has remained open, because spherical symmetry hides the hair's mass as well: its Komar mass vanishes identically and the exact identity $M_V=2Ω_HJ_V$ degenerates to $0=0$. Rotation lifts both degeneracies at once. We construct the rotating solutions of the model, the first in this setting, and find that the hair's mass is not a free parameter but a second-order invariant of the rotational response, fixed by $M_V=2Ω_HJ_V$. Above a coupling threshold the ceiling gives way: the domain of existence crosses the extremal Kerr--Newman bound, reaching $q=Q/M>1$ with $q^2+χ^2$ up to $1.84$, while at $α=5$ the maximum charge stays below it. The shadow is where the hair becomes visible. At $(q,χ)=(0.9947,0.10)$, near the extremal bound, the hair contributes an ellipticity of $8.30\%$, against $0.44\%$ from the charge and $0.06\%$ from rotation --- a factor of $19$ that charging a Kerr black hole cannot mimic; at the overcharged solution $(q,χ)=(1.2527,0.10)$ the total ellipticity reaches $25.6\%$. Whether the branch is ghost-free remains open, but the existing no-go criteria do not settle it: they assume a background and a dispersion relation that do not hold here.

Authors

Publication Details

Journal
arXiv (Cornell University)
Published
2026-10-29
DOI
https://doi.org/10.48550/arxiv.2610.40179
Primary Topic
Black Holes and Theoretical Physics
Type
preprint
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
preprint

Rotation overcharges vectorized black holes

Guangzai Ye, Shengjun Guo, Peng Liu
arXiv (Cornell University)
Black Holes and Theoretical Physics
preprint

Rotation overcharges vectorized black holes

Guangzai Ye, Shengjun Guo, Peng Liu
preprint en

Abstract

A charged black hole has a ceiling: extremality bounds the charge that a given mass and spin can support. Vector hair has so far only lowered it. In the Einstein--Maxwell--Vector (EMV) model, where a massless vector field couples nonminimally to the electromagnetic invariant, the spherically symmetric vectorized Reissner--Nordström black holes are strictly undercharged: vector hair is paid for in charge. Whether this ceiling is a property of the vector field or merely of spherical symmetry has remained open, because spherical symmetry hides the hair's mass as well: its Komar mass vanishes identically and the exact identity $M_V=2Ω_HJ_V$ degenerates to $0=0$. Rotation lifts both degeneracies at once. We construct the rotating solutions of the model, the first in this setting, and find that the hair's mass is not a free parameter but a second-order invariant of the rotational response, fixed by $M_V=2Ω_HJ_V$. Above a coupling threshold the ceiling gives way: the domain of existence crosses the extremal Kerr--Newman bound, reaching $q=Q/M>1$ with $q^2+χ^2$ up to $1.84$, while at $α=5$ the maximum charge stays below it. The shadow is where the hair becomes visible. At $(q,χ)=(0.9947,0.10)$, near the extremal bound, the hair contributes an ellipticity of $8.30\%$, against $0.44\%$ from the charge and $0.06\%$ from rotation --- a factor of $19$ that charging a Kerr black hole cannot mimic; at the overcharged solution $(q,χ)=(1.2527,0.10)$ the total ellipticity reaches $25.6\%$. Whether the branch is ghost-free remains open, but the existing no-go criteria do not settle it: they assume a background and a dispersion relation that do not hold here.

arXiv (Cornell University)
Black Holes and Theoretical Physics
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.

Laika access coming soon