arXiv subjects

Hiroshige Kajiura

Publications and source records attributed to Hiroshige Kajiura.

21 records · Page 2Linked to original sources

arXiv2001

T-Duality Group for Open String Theory

We study T-duality for open strings on tori $\T^d$. The general boundary conditions for the open strings are constructed, and it is shown that T-duality group, which preserves the mass spectrum of closed strings, preserves also the mass spectrum of the open strings. The open strings are transformed to those with different boundary conditions by T-duality. We also discuss the T-duality for D-brane mass spectrum, and show that the D-branes and the open strings with both ends on them are transformed together consistently.

hep-th↗

arXiv2001

Exact Tachyon Condensation on Noncommutative Torus

We construct the exact noncommutative solutions on tori. This gives an exact description of tachyon condensation on bosonic D-branes, non-BPS D-branes and brane-antibrane systems. We obtain various bound states of D-branes after the tachyon condensation. Our results show that these solutions can be generated by applying the gauge Morita equivalence between the constant curvature projective modules. We argue that there is a general framework of the noncommutative geometry based on the notion of Morita equivalence which underlies this specific example.

hep-th↗

arXiv1999

Comments on Large N Matrix Model

The large N Matrix model is studied with attention to the quantum fluctuations around a given diagonal background. Feynman rules are explicitly derived and their relation to those in usual Yang-Mills theory is discussed. Background D-instanton configuration is naturally identified as a discretization of momentum space of a corresponding QFT. The structure of large N divergence is also studied on the analogy of UV divergences in QFT.

hep-th↗