594 citations · 3.1k across the 88 of their papers we have counts for
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Scale Factor Duality and the Energy Condition Inequalities
Sayan Kar
We demonstrate, by a simple analysis, that cosmological line elements related by scale factor duality also exhibit a duality with respect to the conservation/violation of the Weak…
Focusing of timelike worldsheets in a theory of strings
Sayan Kar
An analysis of the generalised Raychaudhuri equations for string world sheets is shown to lead to the notion of focusing of timelike worldsheets in the classical Nambu-Goto theory…
Generalised Raychaudhuri equations for strings in the presence of an antisymmetric tensor field
Sayan Kar
The generalised Raychaudhuri equations derived by Capovilla and Guven are exclusively for extremal, timelike Nambu--Goto membranes. In this article, we construct the corresponding…
Generalised Raychaudhuri Equations for Strings and Membranes
Sayan Kar
A recent generalisation of the Raychaudhuri equations for timelike geodesic congruences to families of dimensional extremal, timelike, Nambu--Goto surfaces embedded in an d…
Stringy black holes and energy conditions
Sayan Kar
The energy condition inequalities for the matter stress energy comprised out of the dilaton and Maxwell fields in the dilaton-Maxwell gravity theories emerging out of string theory…