2017/03/23 by Henrique Gomes, Daniel C. Guariento · 52 citations
Mathematics · Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Classical mechanics #Constant curvature #Cosmology #Cosmology and Gravitation Theories #Curvature #Degrees of freedom (physics and chemistry) #Geometry #Hamiltonian (control theory) #Mathematical physics #Mathematics #Physics #Quantum mechanics #Scalar field #gr-qc #hep-th #math-ph #math.MP
paper · pdf · doi:10.1103/physrevd.95.104049
published in Physical review. D/Physical review. D. 95(10) (American Physical Society) · 10 pages
arxiv created 2017/03/23 · openalex publication_date 2017/05/30 · arxiv updated 2017/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The cuscuton was introduced in the context of cosmology as a field with infinite speed of propagation. It has been claimed to resemble Ho\ifmmode \checkr\else \vr\fiava gravity in a certain limit, and it is a good candidate for an ether theory in which a time-dependent cosmological constant appears naturally. The analysis of its properties is usually performed in the Lagrangian framework, which makes issues like the counting of its dynamical degrees of freedom less clear-cut. Here we perform a Hamiltonian analysis of the theory. We show that the homogeneous limit with local degrees of freedom has singular behavior in the Hamiltonian framework. In other frames, it has an extra scalar degree of freedom. The homogeneous field has regular behavior only if defined a priori as a spatially constant field in a constant mean curvature foliation and contributing with a single global degree of freedom. Lastly, we find conditions on the cuscuton potential for the resulting lapse function to be nonzero throughout evolution.