Other side of a black hole
Pro Research Analysisby 
Searched over 200M research papers
Exploring the Other Side of a Black Hole
Black Hole Event Horizon and Shadow
A defining characteristic of a black hole is its event horizon, which casts a "shadow" due to the bending of light. This shadow is nearly independent of the black hole's spin or orientation and has an apparent diameter of approximately 10 gravitational radii. For the black hole at the Galactic center, Sagittarius A* (Sgr A*), this shadow is predicted to be around 30 microarcseconds in size. Observing this shadow is feasible with current radio interferometry technology, providing a realistic expectation of imaging the event horizon of a black hole in the near future3.
Black Hole Dynamics and Matrix Theory
The dynamics on the other side of a black hole can be described using matrix theory. Near-extremal D-brane thermodynamics can be used to compute the entropy of Schwarzschild black holes. This approach is valid in the regime where black strings, stretched across the longitudinal direction, become unstable and transition into black holes. The appropriate dynamics on the black hole side of this transition involve the zero modes of the corresponding super Yang-Mills theory. This analysis has implications for matrix theory and the holographic principle, suggesting a mean field theory argument for the entropy of black holes in all dimensions1.
Statistical Mechanics of Black Holes
The statistical mechanics of black holes can be understood by reducing the dynamics of a nearly-AdS2 spacetime with boundaries to that of two particles in anti-de Sitter space. This framework allows for the construction of thermal partition functions and arbitrary density matrices using wavefunctions for a two-sided black hole. Additionally, correlation functions of external operators can be obtained, providing a deeper understanding of the statistical mechanics involved2.
Black Hole Production and Signatures
Black hole production at colliders is possible when the colliding energy exceeds the Planck scale, which can be effectively at the TeV scale in models with large extra dimensions. The production process involves subprocesses where black holes and other standard-model particles are produced with significant transverse momentum. The decay of these black holes results in a signature characterized by high multiplicity particles in a boosted spherical shape on one side and a few high transverse momentum partons on the other side. These signatures are useful for identifying black hole production events4.
Wormholes and Gravitational Perturbations
If a traversable wormhole connects two different spacetimes, the flux cannot be conserved separately in each space. Objects near a wormhole in one space will feel the influence of objects in the other space. This effect is particularly interesting in the case of gravity. By studying the orbits of stars around the black hole at the center of our galaxy, we could determine if it harbors a traversable wormhole. Gravitational perturbations from a star on the other side of the wormhole could leave detectable imprints on the orbit of a star on our side. This effect can also be observed in black hole binary systems or black hole-star binary systems. Even non-traversable wormholes can transmit gravitational perturbations to the other side5.
Conclusion
The study of black holes and their other side involves a combination of observational techniques, theoretical frameworks, and experimental signatures. From imaging the event horizon to understanding the dynamics through matrix theory and statistical mechanics, and exploring the potential of wormholes, the research provides a comprehensive view of the complex phenomena associated with black holes. These insights not only enhance our understanding of black holes but also open up new avenues for exploring the fundamental nature of spacetime.
Sources and full results
Most relevant research papers on this topic
Comments on black holes in matrix theory
The entropy of Schwarzschild black holes can be computed in matrix theory using near-extremal D-brane thermodynamics, but the regime in which this approach is valid actually describes black strings stretched across the longitudinal direction.
Highly CitedStatistical mechanics of a two-dimensional black hole
This paper presents the statistical mechanics of a two-dimensional black hole, enabling the construction of thermal partition functions and arbitrary density matrices.
Highly CitedViewing the Shadow of the Black Hole at the Galactic Center
The event horizon of Sgr A*, the Galactic center's black hole, may be observable with submillimeter interferometry within a few years, providing a realistic expectation of imaging the black hole within a few years.
Highly CitedBlack hole production and large extra dimensions.
Black hole production at colliders is possible with high colliding energy and can produce a signature consisting of high multiplicity particles and high p(T) partons when decaying.
Highly CitedObserving a wormhole
A traversable wormhole connects two different spacetimes, influencing objects in one space and affecting those in the other space, with potential applications in black hole orbits and black hole-star binary systems.
The Nature of Black Hole Shadows
The black hole shadow is a distinct visual signature in black holes, resulting from blocking and path-lengthening effects, making it a robust and fairly model-independent observable for deep sub-Eddington regime black holes.
Particle creation by black holes
Quantum mechanical effects cause black holes to create and emit particles as if they were hot bodies, leading to their eventual disappearance and violation of the classical law of event horizon area not decreasing.
Highly CitedNot quite a black hole
The 2-2-hole, a novel horizonless configuration, may be the nearly black end point of gravitational collapse, with a shrinking volume and timelike curvature singularity.
Highly CitedBlack holes in general relativity
A stationary black hole must have a topologically spherical boundary and be axisymmetric if it is rotating, establishing the conjecture that any stationary black hole is a Kerr solution.
Highly CitedBlack hole explosions?
Black holes may have finite lives, with smaller black holes evaporating by now, and their rate of emission being similar to a body with a temperature of 106 (Mcirċ/M)K.
Highly Cited