White Holes as Remnants: A Surprising Scenario for the End of a Black Hole (1802.04264v2)

Abstract: Quantum tunneling of a black hole into a white hole provides a model for the full life cycle of a black hole. The white hole acts as a long-lived remnant, solving the black-hole information paradox. The remnant solution of the paradox has long been viewed with suspicion, mostly because remnants seemed to be such exotic objects. We point out that (i) established physics includes objects with precisely the required properties for remnants: white holes with small masses but large finite interiors; (ii) non-perturbative quantum-gravity indicates that a black hole tunnels precisely into such a white hole, at the end of its evaporation. We address the objections to the existence of white-hole remnants, discuss their stability, and show how the notions of entropy relevant in this context allow them to evade several no-go arguments. A black hole's formation, evaporation, tunneling to a white hole, and final slow decay, form a unitary process that does not violate any known physics.

• The paper shows that quantum tunneling can transform an evaporating black hole into a white hole remnant, addressing the information loss paradox.
• It employs quantum gravitational principles to ensure unitary evolution, reconciling classical black hole dynamics with Hawking radiation effects.
• The research suggests that white hole remnants, characterized by small mass and expansive interiors, could yield observable anomalies in cosmic phenomena.

Quantum Tunneling and White Hole Remnants: Revisiting Black Hole End-Stages

The paper "White Holes as Remnants: A Surprising Scenario for the End of a Black Hole" explores an intriguing resolution to the black hole information paradox by proposing that black holes may transition into remnants in the form of white holes. This hypothesis creatively leverages quantum gravitational effects to provide a novel interpretation of black hole life cycles, asserting viable solutions to long-standing challenges in theoretical physics.

Quantum Tunneling and White Hole Formation

A significant focus of the paper is on the concept that black holes can undergo quantum tunneling, transforming into white holes. This process characterizes the tunneling event as a non-classical phase where a black hole evaporates completely and transitions to another quantum gravitational phase encompassing a white hole. Crucially, this transformation respects the principles of unitary evolution, thereby addressing the black hole information paradox.

The core predicament that drove skepticism about remnant scenarios is their perceived vacuity. White holes, depicted in the paper, offer a concrete structure with small mass and extensive interior volumes—attributes already supported by established physics, mitigating the dilemma of perceived exoticism. The paper argues that white holes can serve as long-lived remnants, providing a venue to store the black hole’s internal information, thus conforming to the conservation laws and principles of quantum mechanics.

Analyzing the Information Paradox and Remnant Viability

The black hole information paradox is predicated on the notion that all information about the particles consumed by a black hole is lost post-evaporation, contravening the principle of unitarity. Traditional views employing event horizons imply irreversible loss, but transitioning to an apparent horizon delineated by this tunneling scenario allows for eventual information release. The formulated white hole accordingly propagates this information in a manner potentially observable, yet governed by lengthy evaporative phases—aligning with constraints on observable signatures.

The paper posits that at the end of its evaporation, a black hole tunnels into a white hole, accompanied by a stabilization rendered by bounded curvature due to quantum gravity effects. Contrary to classical expectations of a violent singularity at the black hole's core, this assumption lends credence to structural continuity post-transition. The authors provide theoretical scaffolding for extended white hole interior volumes, correlating them to the black hole's historic mass.

Furthermore, the interplay of entanglement entropy across the transitioning horizon is meticulously dissected. For a black hole approaching the Planck mass, the Euclidean action implies a probability increase commensurate with diminishing mass which accommodates for Hawking radiation effects. Notably, it suggests a resolution trajectory whereby Hawking radiation gets naturally united, overturning loss presumptions.

Theoretical and Experimental Implications

While verifying the existence of white hole remnants remains a formidable pursuit, their hypothesized characteristics lay a fertile ground for experimental pursuits. The longevity of such remnants suggests possible astroparticle physics exploration scenarios or potential cosmic observations where standard Hawking radiation profiles could exhibit anomalous patterns.

The paper contributes speculatively, yet compellingly, to our understanding of cosmic mechanics and underlines a significant theoretical alternative to mainstream perspectives like firewall hypotheses. It repositions remnants from a theoretical periphery towards an increasingly plausible framework, augmenting ongoing discourses in quantum gravity.

By integrating distinct quantum gravitational theories, the paper sustains a coherent account of black and white hole dynamics that emphasizes classical-genesis discrepancies while expanding quantum mechanical dialogues. As we further probe quantum gravitational predictions and extend empirical inquiries, the propositions within this research could guide new understandings of universal evolution, maintaining intricate balances between classical postulates and quantum conjectures.