arXiv subjects

Danijel Obrić

Publications and source records attributed to Danijel Obrić.

3 recordsLinked to original sources

arXiv2024

T-duality of a bosonic string in a weakly curved space-time

In this article we consider T-dualization of a $3D$ closed bosonic string that is propagating in space-time metric that has infinitesimal linear dependence on the coordinates $x^μ$. Other fields, Kalb-Ramond and dilaton fields are set to zero. Action with this configuration of fields is not invariant to translations. In order to find T-dual theory we will employ generalization of the Buscher procedure that can be applied to such cases where we have coordinate dependent fields that do not possess translational isometry. Finally, using transformation laws that connect coordinates of starting and T-dual theories, we will be able to examine the geometric structure of T-dual theory.

hep-th↗

arXiv2023

Double space T-dualization and coordinate dependent RR

In this article we examine T-dualization in double space formalism of type II superstring theory in pure spinor formulation. Background fields that we consider will all be constant except Ramond-Ramond field which will infinitesimally depend only on bosonic coordinates $x^μ$. In double space T-dual transformations are represented as permutations between starting $x^μ$ and dual coordinates $y_μ$. Combining these two sets of coordinates into double coordinate $Z^M = (x^μ, y_μ)$ while demanding that T-dual double coordinates have same transformation laws, we obtain how background fields transform under T-duality. Comparing these results with ones obtained with Buscher T-dualization procedure we are able to conclude that these two approaches are equivalent for cases where background fields have coordinate dependence.

hep-th↗

arXiv2018

Noncommutativity and nonassociativity of closed bosonic string on T-dual toroidal backgrounds

In this article we consider closed bosonic string in the presence of constant metric and Kalb-Ramond field with one non-zero component, $B_{xy}=Hz$, where field strength $H$ is infinitesimal. Using Buscher T-duality procedure we dualize along $x$ and $y$ directions and using generalized T-duality procedure along $z$ direction imposing trivial winding conditions. After first two T-dualizations we obtain $Q$ flux theory which is just locally well defined, while after all three T-dualizations we obtain nonlocal $R$ flux theory. Origin of non-locality is variable $ΔV$ defined as line integral, which appears as an argument of the background fields. Rewriting T-dual transformation laws in the canonical form and using standard Poisson algebra, we obtained that $Q$ flux theory is commutative one and the $R$ flux theory is noncommutative and nonassociative one. Consequently, there is a correlation between non-locality and closed string noncommutativity and nonassociativity.

hep-th↗