scholarly journals GRAVITY ON NONCOMMUTATIVE D-BRANES

2003 ◽  
Vol 18 (07) ◽  
pp. 1051-1066 ◽  
Author(s):  
F. ARDALAN ◽  
H. ARFAEI ◽  
M. R. GAROUSI ◽  
A. GHODSI

The effective action for the low energy scattering of two gravitons with a D-brane in the presence of a constant antisymmetric B field in bosonic string theory is calculated and the modification to the standard D-brane action to first order in α′ is obtained.

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Mohammad R. Garousi

Abstract Recently, it has been shown that the gauge invariance requires the minimum number of independent couplings for B-field, metric and dilaton at order $$\alpha '^2$$α′2 to be 60. In this paper we fix the corresponding 60 parameters in string theory by requiring the couplings to be invariant under the global T-duality transformations. The Riemann cubed terms are exactly the same as the couplings that have been found by the S-matrix calculations.


1995 ◽  
Vol 10 (07) ◽  
pp. 575-585
Author(s):  
V. V. BELOKUROV ◽  
M. Z. IOFA

Following the ideas of Ref. 3, to account for instability of 2-D black hole solution, we discuss possible imaginary string-loop corrections to the coefficient at the Einstein term in string effective action (EA). In closed bosonic string theory, such corrections appear because of the tachyon contribution to the integration measure over the moduli. In superstring theory, several possible sources of complex one-string-loop contributions to the EA are considered. It is argued that none of them can account for complex corrections to the Einstein term in the effective action.


2005 ◽  
Vol 20 (07) ◽  
pp. 1481-1493
Author(s):  
J. KLUSOŇ

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 space–time metric and marginal tachyon profile is the exact solution of our model even if we take into account backreaction of tachyon on dilaton and on metric.


1989 ◽  
Vol 04 (28) ◽  
pp. 2767-2772 ◽  
Author(s):  
R.G. LEIGH

In a recent paper we discussed, among other things, the effect of duality transformations on the open bosonic string theory. Namely, we conjectured that a macroscopic object, the D-brane, effectively interacts with closed and open string modes in the low energy limit. This conjecture was supported by a string scattering amplitude calculation. In this letter we report on a σ-model calculation in the mixed Dirichlet-Neumann theory. We find an action of the Dirac-Born-Infeld type restricted to (26−k)-dimensions.


2013 ◽  
Vol 2013 (10) ◽  
Author(s):  
Mohammad R. Garousi ◽  
Ahmad Ghodsi ◽  
Tooraj Houri ◽  
Ghadir Jafari

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Mohammad R. Garousi

AbstractIt has been recently observed that the imposition of the O(1, 1) symmetry on the circle reduction of the classical effective action of string theory, can fix the effective action of the bosonic string theory at order $$\alpha '^2$$ α ′ 2 , up to an overall factor. In this paper, we use the cosmological reduction on the action and show that, up to one-dimensional field redefinitions and total derivative terms, it can be written in the O(25, 25)-invariant form proposed by Hohm and Zwiebach.


2002 ◽  
Vol 34 (9) ◽  
pp. 1331-1344
Author(s):  
Alfredo Herrera-Aguilar ◽  
Oleg V. Kechkin

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Davoud Kamani

Abstract The boundary state corresponding to the Dp-brane with a transverse rotation in the presence of the Kalb–Ramond and tachyon background fields and a U(1) internal field will be constructed. We shall investigate effects of the open string tachyon condensation on this brane via its boundary state. We demonstrate that the background fields and transverse rotation cannot protect the brane against the collapse. Our calculations are in the context of the bosonic string theory.


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