scholarly journals Does back reaction enforce the averaged null energy condition in semiclassical gravity?

1996 ◽  
Vol 54 (10) ◽  
pp. 6233-6283 ◽  
Author(s):  
Eanna E. Flanagan ◽  
Robert M. Wald
Keyword(s):  
Energy Condition ◽  
Null Energy Condition ◽  
Back Reaction ◽  
Semiclassical Gravity

scholarly journals DYNAMIC WORMHOLES

1999 ◽  
Vol 08 (03) ◽  
pp. 373-382 ◽  
Author(s):  
SEAN A. HAYWARD
Keyword(s):  
Energy Condition ◽  
Null Energy Condition ◽  
Negative Energy ◽  
Positive Energy ◽  
Back Reaction ◽  
Final State ◽  
Black And White ◽  
Klein Gordon ◽  
Dynamical Description ◽  
New Framework

A new framework is proposed for general dynamic wormholes, unifying them with black holes. Both are generically defined locally by outer trapping horizons, temporal for wormholes and spatial or null for black and white holes. Thus wormhole horizons are two-way traversible, while blackhole and whitehole horizons are only one-way traversible. It follows from the Einstein equation that the null energy condition is violated everywhere on a generic wormhole horizon. It is suggested that quantum inequalities constraining negative energy break down at such horizons. Wormhole dynamics can be developed as for blackhole dynamics, including a reversed second law and a first law involving a definition of wormhole surface gravity. Since the causal nature of a horizon can change, being spatial under positive energy and temporal under sufficient negative energy, blackholes and wormholes are interconvertible. In particular, if a wormhole's negative-energy source fails, it may collapse into a blackhole. Conversely, irradiating a blackhole horizon with negative energy could convert it into a wormhole horizon. This also suggests a possible final state of blackhole evaporation: a stationary wormhole. The new framework allows a fully dynamical description of the operation of a wormhole for practical transport, including the back-reaction of the transported matter on the wormhole. As an example of a matter model, a Klein–Gordon field with negative gravitational coupling is a source for a static wormhole of Morris and Thorne.

scholarly journals ANEC in λϕ4 theory

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Teresa Bautista ◽  
Lorenzo Casarin ◽  
Hadi Godazgar
Keyword(s):  
Critical Points ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Renormalisation Group ◽  
Quartic Coupling ◽  
Third Order ◽  
Expectation Value ◽  
Scalar State

Abstract Motivated by the goal of applying the average null energy condition (ANEC) to renormalisation group flows, we calculate in λϕ4 theory the expectation value of the ANEC operator in a particular scalar state perturbatively up to third order in the quartic coupling and verify the expected CFT answer. The work provides the technical tools for studying the expectation value of the ANEC operator in more interesting states, for example tensorial states relevant to the Hofman-Maldacena collider bounds, away from critical points.

scholarly journals Singularity Theorems in the Effective Field Theory for Quantum Gravity at Second Order in Curvature

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 171
Author(s):  
Folkert Kuipers ◽  
Xavier Calmet
Keyword(s):  
Field Theory ◽  
Quantum Gravity ◽  
Effective Field Theory ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Effective Field ◽  
Second Order ◽  
Jordan Frame ◽  
Singularity Theorems ◽  
Massive Spin

In this paper, we discuss singularity theorems in quantum gravity using effective field theory methods. To second order in curvature, the effective field theory contains two new degrees of freedom which have important implications for the derivation of these theorems: a massive spin-2 field and a massive spin-0 field. Using an explicit mapping of this theory from the Jordan frame to the Einstein frame, we show that the massive spin-2 field violates the null energy condition, while the massive spin-0 field satisfies the null energy condition, but may violate the strong energy condition. Due to this violation, classical singularity theorems are no longer applicable, indicating that singularities can be avoided, if the leading quantum corrections are taken into account.

scholarly journals Wormholes in generalized hybrid metric-Palatini gravity obeying the matter null energy condition everywhere

2018 ◽  
Vol 98 (6) ◽  
Author(s):  
João Luís Rosa ◽  
José P. S. Lemos ◽  
Francisco S. N. Lobo
Keyword(s):  
Energy Condition ◽  
Null Energy Condition

scholarly journals Higher-dimensional evolving wormholes satisfying the null energy condition

2014 ◽  
Vol 90 (2) ◽  
Author(s):  
Mahdi Kord Zangeneh ◽  
Francisco S. N. Lobo ◽  
Nematollah Riazi
Keyword(s):  
Energy Condition ◽  
Null Energy Condition ◽  
Higher Dimensional

scholarly journals Bulk matter and the boundary quantum null energy condition

2018 ◽  
Vol 2018 (8) ◽  
Author(s):  
Zuhair U. Khandker ◽  
Sandipan Kundu ◽  
Daliang Li
Keyword(s):  
Energy Condition ◽  
Null Energy Condition

scholarly journals Possible formation of wormholes from dark matter in an isothermal galactic halo and void

2019 ◽  
Vol 34 (23) ◽  
pp. 1950188
Author(s):  
Nayan Sarkar ◽  
Susmita Sarkar ◽  
Farook Rahaman ◽  
P. K. F. Kuhfittig ◽  
G. S. Khadekar
Keyword(s):  
Dark Matter ◽  
Galactic Halo ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Galactic Rotation ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Rotation Curves ◽  
Galactic Rotation Curves ◽  
Traversable Wormholes

It is well-known that traversable wormholes are valid solutions of the Einstein field equations, but these structures can only be maintained by violating the null energy condition. In this paper, we have obtained such wormhole solutions in an isothermal galactic halo, as well as in a void. We have shown that the null energy condition is violated, with the help of a suitable redshift function obtained from flat galactic rotation curves.

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