ER = EPR is a conjecture in physics stating that two entangled particles (a so-called Einstein–Podolsky–Rosen or EPR pair) are connected by a

wormhole A wormhole (Einstein-Rosen bridge) is a hypothetical structure connecting disparate points in spacetime, and is based on a special Solutions of the Einstein field equations, solution of the Einstein field equations. A wormhole can be visualize ...

(or Einstein–Rosen bridge) and is thought by some to be a basis for unifying

general relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...

and

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...

into a theory of everything.

Overview

The conjecture was proposed by

Leonard Susskind Leonard Susskind (; born June 16, 1940)his 60th birthday was celebrated with a special symposium at Stanford University.in Geoffrey West's introduction, he gives Suskind's current age as 74 and says his birthday was recent. is an American physicis ...

and Juan Maldacena in 2013. They proposed that a wormhole (Einstein–Rosen bridge or ER bridge) is equivalent to a pair of maximally entangled

black holes A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can def ...

. EPR refers to quantum entanglement (

EPR paradox EPR may refer to: Science and technology * EPR (nuclear reactor), European Pressurised-Water Reactor * EPR paradox (Einstein–Podolsky–Rosen paradox), in physics * Earth potential rise, in electrical engineering * East Pacific Rise, a mid-ocea ...

). The symbol is derived from the first letters of the surnames of authors who wrote the first paper on wormholes (

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...

and

Nathan Rosen Nathan Rosen (Hebrew: נתן רוזן; March 22, 1909 – December 18, 1995) was an American-Israeli physicist noted for his study on the structure of the hydrogen atom and his work with Albert Einstein and Boris Podolsky on entangled wave functio ...

) and the first paper on entanglement (Einstein, Boris Podolsky and Rosen). The two papers were published in 1935, but the authors did not claim any connection between the concepts.

Conjectured resolution

This is a conjectured resolution to the AMPS firewall paradox. Whether or not there is a firewall depends upon what is thrown into the other distant black hole. However, as the firewall lies inside the event horizon, no external

superluminal signalling Superluminal communication is a hypothetical process in which information is sent at faster-than-light (FTL) speeds. The current scientific consensus is that faster-than-light communication is not possible, and to date it has not been achieved in ...

would be possible. This conjecture is an extrapolation of the observation by

Mark Van Raamsdonk Mark Van Raamsdonk is a professor at the Department of Physics and Astronomy at the University of British Columbia since 2002. Before that, he was a postdoc at Stanford University from 2000 until 2002 and studied as a graduate student at Princeto ...

that a maximally extended

AdS-Schwarzschild black hole In theoretical physics, an anti-de Sitter (AdS) black hole is a black hole solution of general relativity or its extensions which represents an isolated massive object, but with a negative cosmological constant. Such a solution asymptotically app ...

, which is a non-traversable wormhole, is dual to a pair of maximally entangled thermal conformal field theories via the

AdS/CFT correspondence In theoretical physics, the anti-de Sitter/conformal field theory correspondence, sometimes called Maldacena duality or gauge/gravity duality, is a conjectured relationship between two kinds of physical theories. On one side are anti-de Sitter s ...

. They backed up their conjecture by showing that the pair production of charged black holes in a background

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

leads to entangled black holes, but also, after Wick rotation, to a wormhole. This conjecture sits uncomfortably with the linearity of quantum mechanics. An entangled state is a linear superposition of separable states. Presumably, separable states are not connected by any wormholes, but yet a superposition of such states is connected by a wormhole. The authors pushed this conjecture even further by claiming any entangled pair of particles—even particles not ordinarily considered to be black holes, and pairs of particles with different masses or spin, or with charges which aren't opposite—are connected by Planck scale wormholes. The conjecture leads to a grander conjecture that the geometry of space, time and gravity is determined by entanglement.

References

External links

* Susskind, Leonard
"ER = EPR" or "What's Behind the Horizons of Black Holes?"
Stanford Institute for Theoretical Physics. November. 4, 2014. {{DEFAULTSORT:ER EPR Black holes Conjectures Quantum gravity