Author
D.A. Rasheed
Bio: D.A. Rasheed is an academic researcher from University of Cambridge. The author has contributed to research in topics: Dilaton & String theory. The author has an hindex of 4, co-authored 6 publications receiving 671 citations.
Topics: Dilaton, String theory, Invariant mass, Superstring theory, Wormhole
Papers
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TL;DR: In this paper, it was shown that there is a function of one variable's worth of Lagrangians for a single Maxwell field coupled to gravity whose equations of motion admit electric-magnetic duality.
465 citations
TL;DR: The most general Lagrangian for non-linear electrodynamics coupled to an axion a and a dilaton φ with SL(2, R ) invariant equations of motion was given in this article.
172 citations
TL;DR: In this paper, the spontaneous production of Dyson pairs in electrodynamics coupled to gravity was investigated and the properties of these zero rest mass black holes with regular horizons were discussed.
71 citations
TL;DR: The Born-Infeld Lagrangian for non-linear electrodynamics coupled to an axion and a dilaton is invariant under electric-magnetic duality rotations as discussed by the authors.
Abstract: The most general Lagrangian for non-linear electrodynamics coupled to an axion $a$ and a dilaton $\phi$ with $SL(2,\mbox{\elevenmsb R})$ invariant equations of motion is $$ -\half\left(
abla\phi\right)^2 - \half e^{2\phi}\left(
abla a\right)^2 + \fraction{1}{4}aF_{\mu
u}\star F^{\mu
u} + L_{\rm inv}(g_{\mu
u},e^{-\frac{1}{2}\phi}F_{\rho\sigma}) $$ where $L_{\rm inv}(g_{\mu
u},F_{\rho\sigma})$ is a Lagrangian whose equations of motion are invariant under electric-magnetic duality rotations. In particular there is a unique generalization of Born-Infeld theory admitting $SL(2,\mbox{\elevenmsb R})$ invariant equations of motion.
17 citations
TL;DR: In this article, the spontaneous production of Dyson pairs in electrodynamics coupled to gravity was investigated and the properties of these zero-rest mass black holes were discussed, and it has been argued by Dyson in the context of QED in flat spacetime that perturbative expansions in powers of the electric charge e cannot be convergent because if e is purely imaginary then the vacuum should be unstable to the production of charged pairs.
Abstract: It has been argued by Dyson in the context of QED in flat spacetime that perturbative expansions in powers of the electric charge e cannot be convergent because if e is purely imaginary then the vacuum should be unstable to the production of charged pairs. We investigate the spontaneous production of such Dyson pairs in electrodynamics coupled to gravity. They are found to consist of pairs of zero-rest mass black holes with regular horizons. The properties of these zero rest mass black holes are discussed. We also consider ways in which a dilaton may be included and the relevance of this to recent ideas in string theory. We discuss accelerating solutions and find that, in certain circumstances, the `no strut' condition may be satisfied giving a regular solution describing a pair of zero rest mass black holes accelerating away from one another. We also study wormhole and tachyonic solutions and how they affect the stability of the vacuum.
7 citations
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TL;DR: In this article, the authors studied the stabilization of scalars near a supersymmetric black hole horizon using the equation of motion of a particle moving in a potential and background metric, and they showed that extremal value of the central charge provides the minimal value of BPS mass and of the potential under the condition that the moduli space metric is positive at the critical point.
744 citations
TL;DR: In this article, the authors discuss the role of Dirichlet p-branes as the ends of strings intersecting the brane when the effects of gravity are ignored, and show that certain special Lagrangian submanifolds of C p, p = 3, 4, 5, may be regarded as supersymmetric configurations consisting of pbranes at angles joined by throats which are the sources of global monopoles.
545 citations
TL;DR: In this paper, the authors reproduce the corrections to the 3-form field equations of the D = 10 Type IIA string (a mixture of tree-level and one-loop effects).
531 citations
TL;DR: Using a nonlinear electrodynamics coupled to General Relativity, a new regular exact black hole solution was found in this paper, where the nonlinear theory reduces to the Maxwell one in the weak limit, and the solution corresponds to a charged black hole for |q|≤2s c m≈1.05 m, with metric, curvature invariants, and electric field regular everywhere.
466 citations
16 Aug 1999
TL;DR: In this article, Born-Infeld action and its supersymmetric generalizations in connection with string theory are reviewed and elaborate on some aspects of Born-infeld action, and some properties of bosonic D=4 BI action.
Abstract: We review and elaborate on some aspects of Born-Infeld action and its supersymmetric generalizations in connection with string theory. Contents: BI action from string theory; some properties of bosonic D=4 BI action; N=1 and N=2 supersymmetric BI actions with manifest linear D=4 supersymmetry; four-derivative terms in N=4 supersymmetric BI action; BI actions with `deformed' supersymmetry from D-brane actions; non-abelian generalization of BI action; derivative corrections to BI action in open superstring theory.
405 citations