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Instabilities in the aether

Carroll, Sean M. and Dulaney, Timothy R. and Gresham, Moira I. and Tam, Heywood (2009) Instabilities in the aether. Physical Review D, 79 (6). Art. No. 065011. ISSN 2470-0010.

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We investigate the stability of theories in which Lorentz invariance is spontaneously broken by fixed-norm vector “aether” fields. Models with generic kinetic terms are plagued either by ghosts or by tachyons, and are therefore physically unacceptable. There are precisely three kinetic terms that are not manifestly unstable: a sigma model (∂_µA_ν)^2, the Maxwell Lagrangian F_µνF^µν, and a scalar Lagrangian (∂_µA^µ)^2. The timelike sigma-model case is well defined and stable when the vector norm is fixed by a constraint; however, when it is determined by minimizing a potential there is necessarily a tachyonic ghost, and therefore an instability. In the Maxwell and scalar cases, the Hamiltonian is unbounded below, but at the level of perturbation theory there are fewer degrees of freedom and the models are stable. However, in these two theories there are obstacles to smooth evolution for certain choices of initial data.

Item Type:Article
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Carroll, Sean M.0000-0002-4226-5758
Additional Information:© 2009 American Physical Society. Received 16 January 2009; published 13 March 2009. We are very grateful to Ted Jacobson, Alan Kostelecky, and Mark Wise for helpful comments. This research was supported in part by the U.S. Department of Energy and by the Gordon and Betty Moore Foundation.
Group:Moore Center for Theoretical Cosmology and Physics
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Department of Energy (DOE)UNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Issue or Number:6
Record Number:CaltechAUTHORS:20090508-120529180
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14187
Deposited By: Jason Perez
Deposited On:13 May 2009 18:41
Last Modified:03 Oct 2019 00:47

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