Hamiltonian Analysis of Non-Relativistic Covariant RFDiff Horava-Lifshitz Gravity

We perform the Hamiltonian analysis of non-relativistic covariant Horava-Lifshitz gravity in the formulation presented recently in arXiv:1009.4885. We argue that the resulting Hamiltonian structure is in agreement with the original construction of non-relativistic covariant Ho\v{r}ava-Lifshitz gravity presented in arXiv:1007.2410. Then we extend this construction to the case of RFDiff invariant Ho\v{r}ava-Lifshitz theory. We find well behaved Hamiltonian system with the number of the first and the second class constraints that ensure the correct number of physical degrees of freedom of gravity.Comment: 15 pages, v2. Title changed, major corrections in section 3. performed, corrected typos and references added,v3: additional typos corrected, references added,v4.additional comments added, version published in PR

Hamiltonian Analysis of the Conformal Decomposition of the Gravitational Field

This short note is devoted to the Hamiltonian formulation of the conformal decomposition of the gravitational field that was performed in [gr-qc/0501092]. We also analyze the gauge fixed form of the theory when we fix the conformal symmetry by imposing the condition det g=1.Comment: 12 page

Dynamics of Probe Brane in the Background of Intersecting Fivebranes

This paper is devoted to the study of the dynamics of the Dp-branes, F-strings and M-branes in the background of the system of two stacks of fivebranes in type IIA, IIB and M theory that intersect on the line.Comment: 17.pages, reference adde

Remark about Non-BPS Dp-Brane at the Tachyon Vacuum Moving in Curved Background

This paper is devoted to the study of the dynamics of a non-BPS Dp-brane at the tachyon vacuum that moves in the curved background.Comment: 20 page

String in Horava-Lifshitz Gravity

We generalize recent analysis of the dynamics of point particle in Horava-Lifshitz background to the case of string probe when we replace the Hamiltonian constraint of the Polyakov string with the constraint that breaks Lorentz invariance of target space-time. Then we find corresponding Lagrangian and argue that the world-sheet theory is invariant under foliation preserving diffeomorphism. Finally we discuss the Hamiltonian dynamics and show that this is well defined on condition that the world-sheet lapse function obeys the projectability condition.Comment: 20 pages, references adde

New Models of f(R) Theories of Gravity

We introduce new models of f(R) theories of gravity that are generalization of Horava-Lifshitz gravity.Comment: 16 pages, typos corrected, v2:minor changes, references adde

Note About Redefinition of BRST Operator for Pure Spinor String in General Background

We discuss an analysis presented by N. Berkovits in [arXiv:0712.0324] in the context of classical mechanics and perform its extension to the case of pure spinor string in general background.Comment: 24 pages, references adde

Note About Unstable M3-brane Action

We construct an action for unstable M3-brane in M-theory. We argue that in order to find M3-brane action that upon direct dimensional reduction leads to non-BPS D3-brane action in type IIA theory we have to presume that the background possesses Killing isometry and that this isometry has to be gauged on the world-volume of M3-brane. Then we construct singular tachyon kink on world-volume of M3-brane and we show that the dynamics of resulting topological defect is governed by an action that upon direct dimensional reduction leads to D2-brane in type IIA theory and that is equivalent to standard M2-brane action in flat background.Comment: 20 pages, references adde

A Toy Model of Closed String Tachyon Effective Action

In this paper we propose the toy model of the closed string tachyon effective action that has marginal tachyon profile as its exact solution in case of constant or linear dilaton background. Then we will apply this model for description of two dimensional bosonic string theory. We will find that the background configuration with the spatial dependent linear dilaton, flat spacetime metric and marginal tachyon profile is the exact solution of our model even if we take into account backreaction of tachyon on dilaton and metric.Comment: 17 page

Non-Linear Massive Gravity with Additional Primary Constraint and Absence of Ghosts

We complete the Hamiltonian analysis of specific model of non-linear massive gravity that was started in arXiv:1112.5267. We identify the primary constraint and corresponding secondary constraint. We show that they are the second class constraints and hence they lead to the elimination of the additional scalar mode. We also find that the remaining constraints are the first class constraints with the structure that corresponds to the manifestly diffeomorphism invariant theory. Finally we determine the number of physical degrees of freedom and we show that it corresponds to the number of physical modes of massive gravity.Comment: 13 page