Dynamical aspects of generalized Palatini theories of gravity

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.024013· OSTI ID:21316236

Olmo, Gonzalo J; Sanchis-Alepuz, Helios; Tripathi, Swapnil ^[1]

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1. Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain)

We study the field equations of modified theories of gravity in which the Lagrangian is a general function of the Ricci scalar and Ricci-squared terms in Palatini formalism. We show that the independent connection can be expressed as the Levi-Civita connection of an auxiliary metric which, in particular cases of interest, is related with the physical metric by means of a disformal transformation. This relation between physical and auxiliary metric boils down to a conformal transformation in the case of f(R) theories. We also show with explicit models that the inclusion of Ricci-squared terms in the action can impose upper bounds on the accessible values of pressure and density, which might have important consequences for the early time cosmology and black hole formation scenarios. Our results indicate that the phenomenology of f(R,R{sub {mu}}{sub {nu}}R{sup {mu}}{sup {nu}}) theories is much richer than that of f(R) and f(R{sub {mu}}{sub {nu}}R{sup {mu}}{sup {nu}}) theories and that they also share some similarities with Bekenstein's relativistic theory of MOND.

• OSTI ID: 21316236
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 2 Vol. 80; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BLACK HOLES
COSMOLOGY
DENSITY
FIELD EQUATIONS
GRAVITATION
LAGRANGIAN FUNCTION
METRICS
RELATIVISTIC RANGE
SIMULATION
TRANSFORMATIONS