The dyon charge in noncommutative gauge theories

We present an explicit classical dyon solution for the noncommutative version of the Yang-Mills-Higgs model (in the Prasad-Sommerfield limit) with a tehta term. We show that the relation between classical electric and magnetic charges also holds in noncommutative space. Extending the Noether approach to the case of a noncommutative gauge theory, we analyze the effect of CP violation at the quantum level, induced both by the theta term and by noncommutativity and we prove that the Witten effect formula for the dyon charge remains the same as in ordinary space.Comment: 17 page

N=2 Chern-Simons-Matter Theories Without Vortices

We study ${\cal N}=2$ Chern-Simons-matter theories with gauge group $U_{k_1}(1)\times U_{k_2}(1)$. We find that, when $k_1+k_2=0$, the partition function computed by localization dramatically simplifies and collapses to a single term. We show that the same condition prevents the theory from having supersymmetric vortex configurations. The theories include mass-deformed ABJM theory with $U(1)_{k}\times U_{-k}(1)$ gauge group as a particular case. Similar features are shared by a class of CS-matter theories with gauge group $U_{k_1}(1)\times \cdots \times U_{k_N}(1)$.Comment: 17 page

Self-dual Chern-Simons solitons in noncommutative space

We construct exact soliton solutions to the Chern-Simons-Higgs system in noncommutative space, for non-relativistic and relativistic models. In both cases we find regular vortex-like solutions to the BPS equations which approach the ordinary selfdual non-topological and topological solitons when the noncommutative parameter $\theta$ goes to zero.Comment: 15 pages, 4 figure

A coordinate-dependent superspace deformation from string theory

Starting from a type II superstring model defined on $R^{2,2}\times CY_6$ in a linear graviphoton background, we derive a coordinate dependent $C$-deformed ${\cal N}=1$, $d=2+2$ superspace. The chiral fermionic coordinates $\theta$ satisfy a Clifford algebra, while the other coordinate algebra remains unchanged. We find a linear relation between the graviphoton field strength and the deformation parameter. The null coordinate dependence of the graviphoton background allows to extend the results to all orders in $\alpha'$.Comment: 14 pages, reference added, accepted for publication in JHE