88 research outputs found
On the Monodromies of N=2 Supersymmetric Yang-Mills Theory
We review the generalization of the work of Seiberg and Witten on N=2
supersymmetric SU(2) Yang-Mills theory to SU(n) gauge groups. The quantum
moduli spaces of the effective low energy theory parametrize a special family
of hyperelliptic genus n-1 Riemann surfaces. We discuss the massless spectrum
and the monodromies.Comment: 15p, harvmac/lanlmac with hyperlinks, 4 uuencoded compressed
postscript figures appende
Elliptic Genera and the Landau-Ginzburg Approach to N=2 Orbifolds
We compute the elliptic genera of orbifolds associated with
super--conformal theories which admit a Landau-Ginzburg description. The
identification of the elliptic genera of the macroscopic Landau-Ginzburg
orbifolds with those of the corresponding microscopic orbifolds further
supports the conjectured identification of these theories. For
Kazama-Suzuki models the orbifolds are associated with certain \IZ_p
subgroups of the various coset factors. Based on our approach we also
conjecture the existence of "-type" variants of these theories, their
elliptic genera and the corresponding Landau-Ginzburg potentials.Comment: 27p, uses harvmac (b). negligible change: suppression of the
draftmod
On Heterotic Orbifolds, M Theory and Type I' Brane Engineering
Horava--Witten M theory -- heterotic string duality poses special problems
for the twisted sectors of heterotic orbifolds. In [1] we explained how in M
theory the twisted states couple to gauge fields apparently living on M9 branes
at both ends of the eleventh dimension at the same time. The resolution
involves 7D gauge fields which live on fixed planes of the (T^4/Z_N) x
(S^1/Z_2) x R^{5,1} orbifold and lock onto the 10D gauge fields along the
intersection planes. The physics of such intersection planes does not follow
directly from the M theory but there are stringent kinematic constraints due to
duality and local consistency, which allowed us to deduce the local fields and
the boundary conditions at each intersection. In this paper we explain various
phenomena at the intersection planes in terms of duality between HW and type I'
superstring theories. The orbifold fixed planes are dual to stacks of D6
branes, the M9 planes are dual to O8 orientifold planes accompanied by D8
branes, and the intersections are dual to brane junctions. We engineer several
junction types which lead to distinct patterns of 7D/10D gauge field locking,
7D symmetry breaking and/or local 6D fields. Another aspect of brane
engineering is putting the junctions together; sometimes, the combined effect
is rather spectacular from the HW point of view and the quantum numbers of some
twisted states have to `bounce' off both ends of the eleventh dimension before
their heterotic identity becomes clear. Some models involve D6/O8 junctions
where the string coupling diverges towards the orientifold plane. We use the
heterotic-HW-I' duality to predict what should happen at such junctions.Comment: 118 pages, uses phyzzx, color printer advice
Wilson Loops in the Large N Limit at Finite Temperature
Using a proposal of Maldacena we compute in the framework of the supergravity
description of N coincident D3 branes the energy of a quark anti-quark pair in
the large N limit of U(N) N=4 SYM in four dimensions at finite temperature.Comment: 7 pages, LaTeX2e, 5 eps figures; references added and corrected,
typos correcte
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