Null energy condition and superluminal propagation
Sergei Dubovsky,Sergei Dubovsky,Thomas Gregoire,Thomas Gregoire,Alberto Nicolis,Riccardo Rattazzi +5 more
TLDR
In this paper, the null energy condition is violated in a large class of situations, including isotropic solids and fluids relevant for cosmology, and the existence of superluminal modes is shown to imply the presence of instabilities.Abstract:
We study whether a violation of the null energy condition necessarily implies the presence of instabilities. We prove that this is the case in a large class of situations, including isotropic solids and fluids relevant for cosmology. On the other hand we present several counter-examples of consistent effective field theories possessing a stable background where the null energy condition is violated. Two necessary features of these counter-examples are the lack of isotropy of the background and the presence of superluminal modes. We argue that many of the properties of massive gravity can be understood by associating it to a solid at the edge of violating the null energy condition. We briefly analyze the difficulties of mimicking u H > 0 in scalar tensor theories of gravity.read more
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Dissertation
Aspects of Applied Holography
TL;DR: In this paper, the singular be- haviour of hyperscaling violating (HSV) geometries within an Einstein-Maxwell-dilaton theory with curvature squared corrections was studied.
Journal ArticleDOI
A note on the field-theoretical description of superfluids
Laura Maria Andrianopoli,Riccardo D'Auria,Pietro Antonio Grassi,Pietro Antonio Grassi,Mario Trigiante +4 more
TL;DR: In this paper, a supersymmetric extension of the original works of Dubovksy et al. has been provided, which provides a better parametrization of the fluid dynamics in order to describe the fluid/superfluid phases.
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Adiabatic Media Inflation
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Construction of the Conserved Non-linear Zeta via the Effective Action for Perfect Fluids
TL;DR: In this article, the curvature perturbation is constructed to nonlinear levels, which is expected to evolve time independently on super-horizon scales; in particular, the authors concentrate on the situation where the universe is dominated by a perfect fluid.
References
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Book
The Large Scale Structure of Space-Time
TL;DR: In this paper, the authors discuss the General Theory of Relativity in the large and discuss the significance of space-time curvature and the global properties of a number of exact solutions of Einstein's field equations.
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Type Ia supernova discoveries at z > 1 from the Hubble Space Telescope: Evidence for past deceleration and constraints on dark energy evolution
Adam G. Riess,Louis-Gregory Strolger,John L. Tonry,Stefano Casertano,Henry C. Ferguson,Bahram Mobasher,Peter Challis,Alexei V. Filippenko,Saurabh Jha,Weidong Li,Ryan Chornock,Robert P. Kirshner,Bruno Leibundgut,Mark Dickinson,Mario Livio,Mauro Giavalisco,Charles C. Steidel,Txitxo Benítez,Zlatan Tsvetanov +18 more
TL;DR: For a flat universe with a cosmological constant, the transition between the two epochs is constrained to be at z = 0.46 ± 0.13 as mentioned in this paper, and w = -1.02 ± (and w < -0.76 at the 95% confidence level) for an assumed static equation of state of dark energy.
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Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
Adam G. Riess,Louis-Gregory Strolger,John L. Tonry,Stefano Casertano,Henry C. Ferguson,Bahram Mobasher,Peter Challis,Alexei V. Filippenko,Saurabh Jha,Weidong Li,Ryan Chornock,Robert P. Kirshner,Bruno Leibundgut,Mark Dickinson,Mario Livio,Mauro Giavalisco,Charles C. Steidel,Narciso Benítez,Zlatan Tsvetanov +18 more
TL;DR: In this article, the first conclusive evidence for cosmic deceleration that preceded the current epoch of cosmic acceleration was provided by the discovery of 16 Type Ia supernovae with the Hubble Space Telescope (HST).
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4D Gravity on a Brane in 5D Minkowski Space
TL;DR: In this article, the authors propose a mechanism by which four-dimensional Newtonian gravity emerges on a 3-brane in 5D Minkowski space with an infinite size extra dimension.