Upper Limit to ΩBin Scalar‐Tensor Gravity Theories

The Newtonian limit of metric gravity theories with quadratic Lagrangians

The Newtonian limit of fourth-order gravity is worked out discussing its viability with respect to the standard results of General Relativity. We investigate the limit in the metric approach which, with respect to the Palatini formulation, has been much less studied in the recent literature, due to the higherorder of the field equations. In addition, we refrain from exploiting the formal equiva...

Central and Local Limit Theories in Markov Dependent Random Variables

Gravity and Einstein-Proca-Weyl theories extended to a class of Scalar gravity theories

We extend the recently proved relation between certain models of Non-Riemannian gravitation and Einstein-Proca-Weyl theories to a class of Scalar gravity theories, this is used to present a Black-Hole Dilaton solution with non-Riemannian connection. PACS numbers: 04.20J, 0450, 0425.Dm, 04.40.Nr, 0470-s permanent address, e-mail: [email protected]

How Noncommutative Gauge Theories Couple to Gravity

We study coupling of noncommutative gauge theories on branes to closed string in the bulk. We derive an expression for the gauge theory operator dual to the bulk graviton, both in bosonic string theory and superstring theory. In either case, we find that the coupling is different from what was expected in the literature when the graviton is polarized in the noncommutative directions. In the cas...

Theories of Quantum Gravity

Ju ly 20 0 8 je a n -f ra n co is P o d ev in on the very smallest scales—the voids in between the smallest known elementary particles—by quantum laws and possibly explain it in terms of some fundamental constituents. Superstring theory is often described as the leading candidate to fill this role, but it has not yet provided an answer to any of these pressing questions. Instead, following its ...