Homogeneous conformal string backgrounds
نویسندگان
چکیده
منابع مشابه
Homogeneous Conformal String Backgrounds
We present exact solutions characterised by Bianchi-type I, II, III, V, VI 0 , VI h four-dimensional metric, space-independent dilaton, and vanishing torsion background, for the low energy string eeective action with zero central charge deecit. We show that, in such a context, curvature singularities cannot be avoided, except for the trivial case of at spacetime and constant dilaton. We also pr...
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Generalizing our previous work, we show how O(d, d) transformations can be used to " boost away " in new dimensions the physical singularities that occur generically in cosmological and/or black-hole conformal string backgrounds. As an example, we show how a recent model by Nappi and Witten can be made singularity-free via O(3, 3) boosts involving a fifth dimension.
متن کاملBoosting Away Singularities from Conformal String Backgrounds
Generalizing our previous work, we show how O(d; d) transformations can be used to "boost away" in new dimensions the physical singularities that occur generically in cosmological and/or black-hole conformal string backgrounds. As an example, we show how a recent model by Nappi and Witten can be made singularity-free via O(3; 3) boosts involving a fth dimension.
متن کاملBuilding String Field Theory around Non-conformal Backgrounds
The main limitations of string field theory arise because its present formulation requires a background representing a classical solution, a background defined by a strictly conformally invariant theory. Here we sketch a construction for a gauge-invariant string field action around non-conformal backgrounds. The construction makes no reference to any conformal theory. Its two-dimensional field-...
متن کاملA new class of spatially homogeneous 4D string backgrounds
A new class of spatially homogeneous 4D string backgrounds, the X(d →) according to a recent classification, is presented and shown to contain only five generic types. In contrast to the case of X(d ↑) (which contains as a subclass all possible FRW backgrounds), exact SO(3) isotropy is always broken in the X(d →) class. This is due to the H-field, whose dual is necessarily along a principal dir...
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ژورنال
عنوان ژورنال: Classical and Quantum Gravity
سال: 1995
ISSN: 0264-9381,1361-6382
DOI: 10.1088/0264-9381/12/3/006