Gravitational Vacuum Condensate Stars

Abstract

Gravitational vacuum condensate stars, proposed as the endpoint of gravitational collapse consistent with quantum theory, are reviewed. Gravastars are cold, low entropy, maximally compact objects characterized by a surface boundary layer and physical surface tension instead of an event horizon. Within this thin boundary layer the effective vacuum energy changes rapidly, such that the interior of a non-rotating gravastar is a non-singular static patch of de Sitter space with eq. of state p=-rho. Remarkably, essentially this same result is obtained by extrapolating Schwarzschild's 1916 constant density interior solution to its compact limit, showing how the black hole singularity theorems and the Buchdahl compactness bound are evaded. The surface stress tensor on the horizon is determined by a modification of the Lanczos-Israel junction conditions for null hypersurfaces, which is applied to rotating gravastar solutions as well. The fundamental basis for the quantum phase transition at the horizon is the stress tensor of the conformal anomaly, depending upon a new light scalar field in the low energy effective action for gravity. This scalar conformalon field allows the effective value of the vacuum energy described as a condensate of an exact 4-form abelian gauge field to change at the horizon. The resulting effective theory thus replaces the fixed constant Lambda of classical general relativity, and its apparently unnaturally large sensitivity to UV physics, with a dynamical condensate whose ground state value in empty flat space is zero identically. This provides both a solution to the cosmological constant problem and an effective Lagrangian dynamical framework for the boundary layer and interior of gravitational condensate stars. The status of present observational constraints and prospects for detection of gravastars through their gravitational wave and echo signatures are discussed.

arXiv commentReview article published as Chapter 8, pp. 283-352 in "Regular Black Holes: Towards a New Paradigm of Gravitational Collapse," C. Bambi editor (Springer), 69 pages, 8 figures, Typos fixed, References added and updated

References in corpus (93)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Observation of Gravitational Waves from a Binary Black Hole Merger
• Black Holes: Complementarity or Firewalls?
• General relativity as an effective field theory: The leading quantum corrections
• Information in Black Hole Radiation
• The information paradox: A pedagogical introduction
• Replica Wormholes and the Entropy of Hawking Radiation
• Testing the nature of dark compact objects: a status report
• Is the gravitational-wave ringdown a probe of the event horizon?
• Gravitational Vacuum Condensate Stars
• Using gravitational-wave observations and quasi-universal relations to constrain the maximum mass of neutron stars
• Quantum Gravity in Everyday Life: General Relativity as an Effective Field Theory
• The entropy of Hawking radiation
• Black Hole Shadows, Photon Rings, and Lensing Rings
• Echoes of ECOs: gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale
• Stable gravastars - an alternative to black holes?
• Advection-Dominated Accretion and the Black Hole Event Horizon
• Relationship between Hawking Radiation and Gravitational Anomalies
• Echoes from the Abyss: Tentative evidence for Planck-scale structure at black hole horizons
• On the Foundations of Chiral Perturbation Theory
• The observational evidence for horizons: from echoes to precision gravitational-wave physics
• The Maximum Mass of a Neutron Star
• Tests for the existence of horizons through gravitational wave echoes
• Gravastars must have anisotropic pressures
• A Quartic Conformally Covariant Differential Operator for Arbitrary Pseudo-Riemannian Manifolds (Summary)
• Stable dark energy stars
• How to tell a gravastar from a black hole
• De Sitter Space and Eternity
• First Cosmology Results using Type Ia Supernovae from the Dark Energy Survey: Constraints on Cosmological Parameters
• Gravitational Condensate Stars: An Alternative to Black Holes
• Information Loss
• Weyl Cohomology and the Effective Action for Conformal Anomalies
• No observational proof of the black-hole event-horizon
• Phenomenological aspects of black holes beyond general relativity
• Ergoregion instability of ultra-compact astrophysical objects
• The Black Hole information problem: past, present, and future
• The effective field theory treatment of quantum gravity
• Gravitational wave signatures of the absence of an event horizon. I. Nonradial oscillations of a thin-shell gravastar
• Low significance of evidence for black hole echoes in gravitational wave data
• Quantum Phase Transitions and the Breakdown of Classical General Relativity
• Gravastar Solutions with Continuous Pressures and Equation of State
• Surface Tension and Negative Pressure Interior of a Non-Singular `Black Hole'
• Did GW150914 produce a rotating gravastar?
• Gravastar Shadows
• Conformal Invariance, Dark Energy, and CMB Non-Gaussianity
• On the Instability of Global de Sitter Space to Particle Creation
• The Trace Anomaly and Massless Scalar Degrees of Freedom in Gravity
• On the ergoregion instability in rotating gravastars
• Macroscopic Effects of the Quantum Trace Anomaly
• Tidal deformability and I-Love-Q relations for gravastars with polytropic thin shells
• The Cosmological Constant Problem and Running Vacuum in the Expanding Universe
• Where are all the gravastars? Limits upon the gravastar model from accreting black holes
• I-Love-Q relations for a gravastar and the approach to the black-hole limit
• Two-dimensional gravitational anomalies, Schwinger terms and dispersion relations
• Stability of a vacuum nonsingular black hole
• The Event Horizon of M87
• Renormalised 3-point functions of stress tensors and conserved currents in CFT
• Echoes from Quantum Black Holes
• Quantum Vacuum Instability of 'Eternal' de Sitter Space
• Gravitational echoes from macroscopic quantum gravity effects
• Gravastar energy conditions revisited
• Parameter estimation of gravitational wave echoes from exotic compact objects
• Instability of hyper-compact Kerr-like objects
• Slowly rotating thin shell gravastars
• Physical States of the Quantum Conformal Factor
• Emergent Relativity
• TTT in CFT: Trace Identities and the Conformal Anomaly Effective Action
• Generic thin-shell gravastars
• Gravastar under the framework of Braneworld Gravity
• Measurement of the Running of the Electromagnetic Coupling at Large Momentum-Transfer at LEP
• Decay of the de Sitter Vacuum
• Anomaly Poles as Common Signatures of Chiral and Conformal Anomalies
• On the radial stability of ultra compact Schwarzschild stars beyond the Buchdahl limit
• Horizon Holography
• Structure of Lanczos-Lovelock Lagrangians in Critical Dimensions
• Bounds on the interior geometry and pressure profile of static fluid spheres
• Slowly rotating super-compact Schwarzschild stars
• Towards a solution of the cosmological constant problem
• A Semi-analytic Study of Axial Perturbations of Ultra Compact Stars
• Observational evidence for the formation of trapping horizons in astrophysical black holes
• The Effective Theory of Gravity and Dynamical Vacuum Energy
• Where is Love? Tidal deformability in the black hole compactness limit
• Scalar Gravitational Waves in the Effective Theory of Gravity
• The self-screening Hawking atmosphere
• Surface Stress Tensor and Junction Conditions on a Rotating Null Horizon
• Generalized no-hair theorems without horizons
• Fermion Pairing and the Scalar Boson of the 2D Conformal Anomaly
• Report of the Topical Group on Cosmic Probes of Fundamental Physics for for Snowmass 2021
• Quantum Effects of the Conformal Anomaly in a 2D Model of Gravitational Collapse
• TF1 Snowmass Report: Quantum gravity, string theory, and black holes
• Quantum Theory and the Nature of Gravitation
• Dark Energy Stars

Cited by in corpus (10)

• Towards a Non-singular Paradigm of Black Hole Physics
• Primordial regular black holes as all the dark matter. I. Time-radial-symmetric metrics
• GW241011 and GW241110: Exploring Binary Formation and Fundamental Physics with Asymmetric, High-Spin Black Hole Coalescence
• Thermodynamics and decay of de Sitter vacuum
• Can gravitational vacuum condensate stars be a dark energy source?
• Quantum Effects of the Conformal Anomaly in a 2D Model of Gravitational Collapse
• Einstein ring of dust shells with quantum hair
• Energy conditions in static, spherically symmetric spacetimes and effective geometries
• Testing General Relativity with Black Hole X-Ray Data and ABHModels
• Shadow of a Noncommutative Thin-Shell Gravastar