523 research outputs found
Spontaneous Z2 Symmetry Breaking in the Orbifold Daughter of N=1 Super Yang-Mills Theory, Fractional Domain Walls and Vacuum Structure
We discuss the fate of the Z2 symmetry and the vacuum structure in an
SU(N)xSU(N) gauge theory with one bifundamental Dirac fermion. This theory can
be obtained from SU(2N) supersymmetric Yang--Mills (SYM) theory by virtue of Z2
orbifolding. We analyze dynamics of domain walls and argue that the Z2 symmetry
is spontaneously broken. Since unbroken Z2 is a necessary condition for
nonperturbative planar equivalence we conclude that the orbifold daughter is
nonperturbatively nonequivalent to its supersymmetric parent. En route, our
investigation reveals the existence of fractional domain walls, similar to
fractional D-branes of string theory on orbifolds. We conjecture on the fate of
these domain walls in the true solution of the Z2-broken orbifold theory. We
also comment on relation with nonsupersymmetric string theories and
closed-string tachyon condensation.Comment: 37 pages, 7 figures. v2: various significant changes; revisions
explained in the introduction. Final version to appear in Phys.Rev.
Dualities in integrable systems and N=2 theories
We discuss dualities of the integrable dynamics behind the exact solution to
the N=2 SUSY YM theory. It is shown that T duality in the string theory is
related to the separation of variables procedure in dynamical system. We argue
that there are analogues of S duality as well as 3d mirror symmetry in the
many-body systems of Hitchin type governing low-energy effective actions.Comment: 16 pages, Latex, Talk given at QFTHEP-99, Moscow, May 27-June
Deconfinement at the Argyres-Douglas point in SU(2) gauge theory with broken N=2 supersymmetry
We consider chiral condensates in SU(2) gauge theory with broken N=2
supersymmetry. The matter sector contains an adjoint multiplet and one
fundamental flavor. Matter and gaugino condensates are determined by
integrating out the adjoint field. The only nonperturbative input is the
Affleck-Dine-Seiberg (ADS) superpotential generated by one instanton plus the
Konishi anomaly. These results are consistent with those obtained by the
`integrating in' procedure, including a reproduction of the Seiberg-Witten
curve from the ADS superpotential. We then calculate monopole, dyon, and charge
condensates using the Seiberg-Witten approach. We show that the monopole and
charge condensates vanish at the Argyres-Douglas point where the monopole and
charge vacua collide. We interpret this phenomenon as a deconfinement of
electric and magnetic charges at the Argyres-Douglas point.Comment: LaTeX file, 21 pages, no figures. Dependence of monopole condensate
on Yukawa coupling is corrected, references adde
Anomalous Zero Sound
We show that the anomalous term in the current, recently suggested by Son and
Yamamoto, modifies the structure of the zero sound mode in the Fermi liquid in
a magnetic field.Comment: 14 pages, 2 figure
Spectral Duality in Integrable Systems from AGT Conjecture
We describe relationships between integrable systems with N degrees of
freedom arising from the AGT conjecture. Namely, we prove the equivalence
(spectral duality) between the N-cite Heisenberg spin chain and a reduced gl(N)
Gaudin model both at classical and quantum level. The former one appears on the
gauge theory side of the AGT relation in the Nekrasov-Shatashvili (and further
the Seiberg-Witten) limit while the latter one is natural on the CFT side. At
the classical level, the duality transformation relates the Seiberg-Witten
differentials and spectral curves via a bispectral involution. The quantum
duality extends this to the equivalence of the corresponding Baxter-Schrodinger
equations (quantum spectral curves). This equivalence generalizes both the
spectral self-duality between the 2x2 and NxN representations of the Toda chain
and the famous AHH duality
Type I Superconductivity upon Monopole Condensation in Seiberg-Witten Theory
We study the confinement scenario in N=2 supersymmetric SU(2) gauge theory
near the monopole point upon breaking of N=2 supersymmetry by the adjoint
matter mass term. We confirm claims made previously that the
Abrikosov-Nielsen-Olesen string near the monopole point fails to be a BPS state
once next-to-leading corrections in the adjoint mass parameter taken into
account. Our results shows that type I superconductivity arises upon monopole
condensation. This conclusion allows us to make qualitative predictions on the
structure of the hadron mass spectrum near the monopole point.Comment: LaTex, 25 pages. Minor changes. To be published in NP
Low energy theorems and the Dirac operator spectral density in QCD
We discuss the behaviour of the spectral density of the massless Dirac
operator at the small eigenvalues and quark masses compatible with the
restrictions imposed by the low energy theorems in QCD. Sum rule for its
derivative over the quark mass is found.Comment: Latex, 6 pages, minor changes and reference adde
Global AdS Picture of 1/2 BPS Wilson Loops
We study the holographic dual string configuration of 1/2 BPS circular Wilson
loops in N=4 super Yang-Mills theory by using the global coordinate of AdS. The
dual string worldsheet is given by the Poincare disk AdS_2 sitting at a
constant global time slice of AdS_5. We also analyze the correlator of two
concentric circular Wilson loops from the global AdS perspective and study the
phase transition associated with the instability of annulus worldsheet
connecting the two Wilson loops.Comment: 14 pages, 3 figures, v2: discussion on two branches corrected, v3:
reference adde
Quantum Vortex Strings: A Review
The quantum worldsheet dynamics of vortex strings contains information about
the 4d non-Abelian gauge theory in which the string lives. Here I tell this
story. The string worldsheet theory is typically some variant of the CP^{N-1}
sigma-model, describing the orientation of the string in a U(N) gauge group.
Qualitative parallels between 2d sigma-models and 4d non-Abelian gauge theories
have been known since the 1970s. The vortex string provides a quantitative link
between the two. In 4d theories with N=2 supersymmetry, the exact BPS spectrum
of the worldsheet coincides with the bulk spectrum in 4d. Moreover, by tuning
parameters, the CP^{N-1} sigma-model can be coaxed to flow to an interacting
conformal fixed point which is related to the 4d Argyres-Douglas fixed point.
For theories with N=1 supersymmetry, the worldsheet theory suffers dynamical
supersymmetry breaking and, more interestingly, supersymmetry restoration, in a
way which captures the physics of Seiberg's quantum deformed moduli space.Comment: Adams Prize Essay. 40 pages with 4 colourful picture
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