arXiv subjects
Publications and source records attributed to Gautam Sengupta.
We present a class of BPS solutions of the IIB Matrix Theory which preserve 1/4 supersymmetry. The solutions desrcibe D-string configurations with left-moving oscillations. We demonstrate that the one-loop quantum effective action of Matrix Theory vanishes for this solution, confirming its BPS nature. We also study the world-volume gauge theory of oscillating strings and show its connection with static D-strings.
A geometrical approach in the non-symmetric connection framework is employed to examine the issue of higher order $α'$ corrections to D=10 type IIB superstring backgrounds with a covariantly constant null Killing isometry and non-zero Ramond-Ramond field content. These describe generalized supersymmetric string waves and were obtained recently by us through the S-duality transformation of purely NS-NS plane wave backgrounds. We find that the backgrounds are exact subject to the existence of certain field redefinitions and provided certain restrictive conditions are satisfied.
A family of type IIB superstring backgrounds involving Ramond-Ramond fields are obtained in ten dimensions starting from a K-model through a generalization of our recent results. The unbroken global $SL(2,R)$ symmetry of the type IIB equations of motion are implemented in this context as a solution generating transfromation. A geometrical analysis, based on the tensor structure of the higher order $α^{\prime}$ terms in the equations of motion, is employed to show that these backgrounds are exact.
We obtain a family of type IIB superstring backgrounds involving Ramond-Ramond fields in ten dimensions starting from a heterotic string background with vanishing gauge fields. To this end the global $SL(2,R)$ symmetry of the type IIB equations of motion is implemented as a solution generating transformation. Using a geometrical analysis we show that the type IIB backgrounds obtained are solutions to all orders in $α^{\prime}$.
It is shown that the asymmetric chiral gauging of the WZW models give rise to consistent string backgrounds. The target space structure of the ${[{SL(2,\Re)/ {SO(1,1)}}]}_L \bigotimes {[{SL(2,\Re)/U(1)}]}_R$ model is analyzed and the presence of a hidden isometry in this background is demonstrated. A nonlinear coordinate transformation is obtained which transforms the asymmetric model to the symmetric one, analyzed recently by two of the present authors.
An exact conformal field theory describing a four dimensional singular string background is obtained by chiral gauging a $U(1)$ subgroup along with translations in $R$ of an $SL(2,R)\times R$ Wess-Zumino-Witten model. It is shown that the target space-time describes a four dimensional black membrane. Furthermore various duality transformed solutions are constructed. These are also shown to correspond to various forms of four dimensional black membranes.