scholarly journals Entanglement entropy of de Sitter space α -vacua

2016 ◽  
Vol 910 ◽  
pp. 23-29 ◽  
Author(s):  
Norihiro Iizuka ◽  
Toshifumi Noumi ◽  
Noriaki Ogawa
Keyword(s):  
Entanglement Entropy ◽  
De Sitter Space ◽  
De Sitter

scholarly journals De Sitter entropy as holographic entanglement entropy

2021 ◽  
Author(s):  
Nikolaos Tetradis
Keyword(s):  
Effective Action ◽  
Degrees Of Freedom ◽  
Entanglement Entropy ◽  
De Sitter Space ◽  
Conformal Anomaly ◽  
Dual Theory ◽  
De Sitter ◽  
Logarithmic Corrections ◽  
Holographic Entanglement Entropy ◽  
Gravitational Entropy

We review the results of refs. [1,2], in which the entanglement entropy in spaces with horizons, such as Rindler or de Sitter space, is computed using holography. This is achieved through an appropriate slicing of anti-de Sitter space and the implementation of a UV cutoff. When the entangling surface coincides with the horizon of the boundary metric, the entanglement entropy can be identified with the standard gravitational entropy of the space. For this to hold, the effective Newton's constant must be defined appropriately by absorbing the UV cutoff. Conversely, the UV cutoff can be expressed in terms of the effective Planck mass and the number of degrees of freedom of the dual theory. For de Sitter space, the entropy is equal to the Wald entropy for an effective action that includes the higher-curvature terms associated with the conformal anomaly. The entanglement entropy takes the expected form of the de Sitter entropy, including logarithmic corrections.

scholarly journals Emergent Gravity and the Dark Universe

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Erik Verlinde
Keyword(s):  
Black Hole Physics ◽  
Entanglement Entropy ◽  
Microscopic Theory ◽  
De Sitter Space ◽  
Elastic Response ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Baryonic Mass ◽  
Entanglement Structure ◽  
Area Law

Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a_0 =cH_0a0=cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.

scholarly journals Entanglement entropy of α-vacua in de Sitter space

2014 ◽  
Vol 2014 (7) ◽  
Author(s):  
Sugumi Kanno ◽  
Jeff Murugan ◽  
Jonathan P. Shock ◽  
Jiro Soda
Keyword(s):  
Entanglement Entropy ◽  
De Sitter Space ◽  
De Sitter

scholarly journals Entanglement entropy in de Sitter space

2013 ◽  
Vol 2013 (2) ◽  
Author(s):  
Juan Maldacena ◽  
Guilherme L. Pimentel
Keyword(s):  
Entanglement Entropy ◽  
De Sitter Space ◽  
De Sitter

scholarly journals Islands in de Sitter space

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Vijay Balasubramanian ◽  
Arjun Kar ◽  
Tomonori Ugajin
Keyword(s):  
Black Hole ◽  
Entanglement Entropy ◽  
De Sitter Space ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Replica Trick ◽  
Compact Geometry ◽  
Entropy Growth ◽  
Spatial Section ◽  
Conventional Field

Abstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of the de Sitter geometry, and find a competition between conventional field theory entanglement entropy and the surface area of extremal “islands” in the de Sitter geometry. The black hole and cosmological horizons both play a role in generating such islands in the backreacted geometry, and have the effect of stabilizing the entropy growth as required by monogamy. We first show this in a scenario in which the de Sitter spatial section has been decompactified to an interval. Then we consider the compact geometry, and argue for a novel interpretation of the island formula in the context of closed universes that recovers the Page curve. Finally, we comment on the application of our construction to the cosmological horizon in empty de Sitter space.

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