7 research outputs found
Construction of the effective action in nonanticommutative supersymmetric field theories
We develop a general gauge invariant construction of the one-loop effective
action for supersymmetric gauge field theories formulated in
superspace. Using manifestly covariant techniques (the background superfield
method and proper-time representations) adopted to the
superspace we show how to define unambiguously the effective action of a matter
multiplet (in fundamental and adjoint representations) and the vector multiplet
coupled to a background gauge superfield. As an application of
this construction we exactly calculate the low-energy one-loop effective action
of matter multiplet and SU(2) SYM theory on the Abelian background.Comment: 14 pages, LaTe
Instantons in N=1/2 Super Yang-Mills Theory via Deformed Super ADHM Construction
We study an extension of the ADHM construction to give deformed
anti-self-dual (ASD) instantons in N=1/2 super Yang-Mills theory with U(n)
gauge group. First we extend the exterior algebra on superspace to
non(anti)commutative superspace and show that the N=1/2 super Yang-Mills theory
can be reformulated in a geometrical way. By using this exterior algebra, we
formulate a non(anti)commutative version of the super ADHM construction and
show that the curvature two-form superfields obtained by our construction do
satisfy the deformed ASD equations and thus we establish the deformed super
ADHM construction. We also show that the known deformed U(2) one instanton
solution is obtained by this construction.Comment: 32 pages, LaTeX, v2: typos corrected, references adde
Non(anti)commutative N=(1,1/2) Supersymmetric U(1) Gauge Theory
We study a reduction of deformation parameters in non(anti)commutative N=2
harmonic superspace to those in non(anti)commutative N=1 superspace. By this
reduction we obtain the exact gauge and supersymmetry transformations in the
Wess-Zumino gauge of non(anti)commutative N=2 supersymmetric U(1) gauge theory
defined in the deformed harmonic superspace. We also find that the action with
the first order correction in the deformation parameter reduces to the one in
the N=1 superspace by some field redefinition. We construct deformed N=(1,1/2)
supersymmetry in N=2 supersymmetric U(1) gauge theory in non(anti)commutative
N=1 superspace.Comment: 30 pages, LaTeX, V2: a reference adde
N=1/2 quiver gauge theories from open strings with R-R fluxes
We consider a four dimensional N=1 gauge theory with bifundamental matter and
a superpotential, defined on stacks of fractional branes. By turning on a flux
for the R-R graviphoton field strength and computing open string amplitudes
with insertions of R-R closed string vertices, we introduce a
non-anticommutative deformation and obtain the N=1/2 version of the theory. We
also comment on the appearance of a new structure in the effective Lagrangian.Comment: 30 pages, 5 figures, JHEP class (included); some comments and a
reference adde
Nonanticommutative Deformation of N=4 SYM Theory: The Myers Effect and Vacuum States
We propose a deformation of SYM theoery induced by
nonanticommutative star product. The deformation introduces new bosonic terms
which we identify with the corresponding Myers terms of a stack of D3-branes in
the presence of a five-form RR flux. We take this as an indication that the
deformed lagrangian describes D3-branes in such a background. The vacuum states
of the theory are also examined. In a specific case where the U(1) part of the
gauge field is nonvanishing the (anti)holomorphic transverse coordinates of the
brane sit on a fuzzy two sphere. For a supersymmetric vacuum the
antiholomorphic coordinates must necessarily commute. However, we also
encounter non-supersymmetric vacua for which the antiholomorphic coordinates do
not commute.Comment: 14 pages, minor changes, refs. adde
Heat kernel and number theory on NC-torus
The heat trace asymptotics on the noncommutative torus, where generalized
Laplacians are made out of left and right regular representations, is fully
determined. It turns out that this question is very sensitive to the
number-theoretical aspect of the deformation parameters. The central condition
we use is of a Diophantine type. More generally, the importance of number
theory is made explicit on a few examples. We apply the results to the spectral
action computation and revisit the UV/IR mixing phenomenon for a scalar theory.
Although we find non-local counterterms in the NC theory on \T^4, we
show that this theory can be made renormalizable at least at one loop, and may
be even beyond