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Toni Ramirez

Publications and source records attributed to Toni Ramirez.

5 recordsLinked to original sources
arXiv2005

Brane Dualities in Non-relativistic Limit

We analyze brane dualities in the non-relativistic limit of the worldvolume actions. In particular we have analyzed how the non-relativistic M2-brane is related via these dualities to non-relativistic D2-brane, non-relativistic IIA fundamental string and also, by using T-duality, to non-relativistic D1-string. These actions coincide with ones obtained from relativistic actions by taking non-relativistic limit, showing that the non-relativistic limit and the dualities commute in these cases.

hep-th↗
arXiv2005

Non Relativistic Dp Branes

We construct a kappa-symmetric and diffeomorphism-invariant non-relativistic Dp-brane action as a non-relativistic limit of a relativistic Dp-brane action in flat space. In a suitable gauge the world-volume theory is given by a supersymmetric free field theory in flat spacetime in p+1 dimensions of bosons, fermions and gauge fields.

hep-th↗
arXiv2004

Physical Degrees of Freedom of Non-local Theories

We analyze the physical (reduced) space of non-local theories, around the fixed points of these systems, by analyzing: i) the Hamiltonian constraints appearing in the 1+1 formulation of those theories, ii) the symplectic two form in the surface on constraints. P-adic string theory for spatially homogeneous configurations has two fixed points. The physical phase space around $q=0$ is trivial, instead around $q=\frac 1g$ is infinite dimensional. For the special case of the rolling tachyon solutions it is an infinite dimensional lagrangian submanifold. In the case of string field theory, at lowest truncation level, the physical phase space of spatially homogeneous configurations is two dimensional around $q=0$, which is the relevant case for the rolling tachyon solutions, and infinite dimensional around $q=\frac {M^2}g$.

hep-th↗
arXiv2002

Supergravity Duals of Noncommutative Wrapped D6 Branes and Supersymmetry without Supersymmetry

We construct the supergravity solution in 11 dimensions describing D6-branes wrapped around a Kahler four-cycle with a B-field along the flat directions of the brane. The configuration is dual to an N=2 noncommutative gauge theory in 2+1 dimensions. We also construct the four associated independent Killing spinors. The phenomenon of supersymmetry without supersymmetry appears naturally when compactifying to type IIA or 8d gauged supergravity. Therefore, this solution also provides an 11d background with four supercharges and four-form flux, which is not obtainable from 8d gauged supergravity.

hep-th↗