Causal field theory with an infinite speed of sound
By N. Afshordi, D. Chung, G. Geshnizjani. 2006
203 citations recorded by the source corpus.
We introduce a model of scalar field dark energy, Cuscuton, which can be realized as the incompressible (or infinite speed of sound) limit of a scalar field theory with a noncanonical kinetic term (or k-essence). Even though perturbations of Cuscuton propagate superluminally, we show that they have a locally degenerate phase space volume (or zero entropy), implying that they cannot carry any microscopic information, and thus the theory is causal. Even coupling to ordinary scalar fields cannot lead to superluminal signal propagation. Furthermore, we show that the family of constant field hypersurfaces is the family of constant mean curvature hypersurfaces, which are the analogs of soap films (or soap bubbles) in Euclidian space. This enables us to find the most general solution in 1+1 dimensions, whose properties motivate conjectures for global degeneracy of the phase space in higher dimensions. Finally, we show that the Cuscuton action can model the continuum limit of the evolution of a field with discrete degrees of freedom and argue why it is protected against quantum corrections at low energies. While this paper mainly focuses on interesting features of Cuscuton in a Minkowski space-time, a companion paper examines cosmology with Cuscuton dark energy.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/18fdaa7eb7bb7aa5241119b181fa0d5721822c14
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In Astronomy and Astrophysics
- Marika Taylor
- Paul McFadden
- Kostas Skenderis
- G. Compère
- V. Hubeny
- Ioannis Papadimitriou
- M. Rangamani
- K. Narayan
In Nuclear and High Energy Physics
- Marika Taylor
- Kostas Skenderis
- Paul McFadden
- G. Compère
- Ioannis Papadimitriou
- Ingmar Kanitscheider
- B. C. Rees
- V. Hubeny
Citations in the corpus
- Massive Cosmologies (2011, unknown): “This procedure defines the mass term (along with the interaction potential in the Lagrangian density) in massive GR L = M 2 Pl 2 √ −g [ R−m2 ( KµνKνµ − (Kαα)2 )] .”
- The holographic fluid dual to vacuum Einstein gravity (2011, background): “(2)Interestingly, this action has also been investigated in the context of dark energy, see [17, 18].”