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Claudio A. Scrucca

Publications and source records attributed to Claudio A. Scrucca.

41 records · Page 3Linked to original sources

Interaction of D-branes on orbifolds and massless particle emission

We discuss various D-brane configurations in 4-dimensional orbifold compactifications of type II superstring theory which are point-like 0-branes from the 4-dimensional space-time point of view. We analyze their interactions and compute the amplitude for the emission of a massless NSNS boson from them, in the case where the branes have a non vanishing relative velocity. In the large distance limit, we compare our computation to the expected field theory results, finding complete agreement.

hep-th↗

Aspects of D-brane dynamics on orbifolds

We discuss D-brane dynamics in orbifold compactifications of type II superstring theory. We compute the interaction potential between two D-branes moving with constant velocities and give a field theory interpretation of it in the large distance limit.

hep-th↗

Closed string radiation from moving D-branes

We compute the amplitude for the radiation of massless NS-NS closed string states from the interaction of two moving D-branes. We consider particle-like D-branes with reference to 4-dimensional spacetime, in toroidal and orbifold compactifications, and we work out the relevant world sheet propagators within the moving boundary state formalism. We find no on-shell axion emission. For large inter-brane separation, we compute the spacetime graviton emission amplitude and estimate the average energy radiated, whereas the spacetime dilaton amplitude is found to vanish in this limit. The possibility of emission of other massless states depends on the nature of the branes and of the compactification scheme.

hep-th↗

Thermodynamics of vortex lines in layered superconductors

We study the dissipative thermodynamics of vortex lines in layered superconductors within a simple string model in the dilute limit of negligible vortex interactions and compute the specific heat $C_v$ in presence of arbitrary dissipation. The interplay of dissipation, inertia and elasticity is shown to control the qualitative thermodynamical behavior and their relative amount determines two very distinct regimes for the specific heat. In the dissipation dominated case we find a behavior $C_v \sim \sqrt{T}$ for a large interval of temperature below $T_c$.

cond-mat↗

Interaction of moving D-branes on orbifolds

We use the boundary state formalism to study the interaction of two moving identical D-branes in the Type II superstring theory compactified on orbifolds. By computing the velocity dependence of the amplitude in the limit of large separation we can identify the nature of the different forces between the branes. In particular, in the Z_3 orbifold case we find a boundary state which is coupled only to the N=2 graviton multiplet containing just a graviton and a vector like in the extremal Reissner-Nordström configuration. We also discuss other cases including $T_4/Z_2$.

hep-th↗