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Resolution of stringy singularities by noncommutative algebras
 JHEP 0106
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New results on superconformal quivers
 JHEP 0604 (2006) 032 [arXiv:hepth/0411262
"... Abstract: All superconformal quivers are shown to satisfy the relation c = a and are thus good candidates for being the field theory living on D3 branes probing CY singularities. We systematically study 3 block and 4 block chiral quivers which admit a superconformal fixed point of the RG equation. M ..."
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Cited by 9 (2 self)
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Abstract: All superconformal quivers are shown to satisfy the relation c = a and are thus good candidates for being the field theory living on D3 branes probing CY singularities. We systematically study 3 block and 4 block chiral quivers which admit a superconformal fixed point of the RG equation. Most of these theories are known to arise as living on D3 branes at a singular CY manifold, namely complex cones over del Pezzo surfaces. In the process we find a procedure of getting a new superconformal quiver from a known one. This procedure is termed “shrinking ” and, in the 3 block case, leads to the discovery of two new models. Thus, the number of superconformal 3 block quivers is 16 rather than the previously known 14. We prove that this list exausts all the possibilities. We suggest that all rank 2 chiral quivers are either del Pezzo quivers or can be obtained by shrinking a del Pezzo quiver and verify this statement for all 4 block quivers, where a lot of “shrunk ” del Pezzo models exist. Contents
Finite Heisenberg groups from nonabelian orbifold quiver gauge theories
, 2007
"... A large class of orbifold quiver gauge theories admits the action of finite Heisenberg groups of the form ∏ i Heis(Zq i × Zq i). For an Abelian orbifold generated by Γ, the Zq i shift generator in each Heisenberg group is one cyclic factor of the Abelian group Γ. For general nonAbelian Γ, however, ..."
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Cited by 4 (1 self)
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A large class of orbifold quiver gauge theories admits the action of finite Heisenberg groups of the form ∏ i Heis(Zq i × Zq i). For an Abelian orbifold generated by Γ, the Zq i shift generator in each Heisenberg group is one cyclic factor of the Abelian group Γ. For general nonAbelian Γ, however, we find that the shift generators are the cyclic factors in the Abelianization of Γ. We explicitly show this for the case Γ = ∆(27), where we construct the finite Heisenberg group symmetries of the field theory. These symmetries are dual to brane number operators counting branes on homological torsion cycles, which therefore do not commute. We compare our field theory results with string
Preprint typeset in JHEP style HYPER VERSION Consistency Conditions on SMatrix of Spin 1 Massless Particles
, 811
"... Abstract: Motivated by new techniques in the computation of scattering amplitudes of massless particles in four dimensions, like BCFW recursion relations, the question that how much structure of the Smatrix can be determined from purely Smatrix arguments has received new attention. The BCFW recurs ..."
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Abstract: Motivated by new techniques in the computation of scattering amplitudes of massless particles in four dimensions, like BCFW recursion relations, the question that how much structure of the Smatrix can be determined from purely Smatrix arguments has received new attention. The BCFW recursion relations for massless particles of spin 1 and 2 imply that the whole treelevel Smatrix can be determined in terms of threeparticle amplitudes (evaluated at complex momenta). However, the known proofs of the validity of the relations rely on the Lagrangian of the theory, either by using Feynman diagrams explicitly or by studying the effective theory at large complex momenta. This means that a purely Smatrix theoretic proof of the relations is still missing. The aim of this paper is to provide such a proof for spin 1 particles by extending the fourparticle test introduced by Benincasa and Cachazo in [1] to all particles. We show how nparticle tests imply that the rational function built from the BCFW recursion relations possesses all the correct factorization channels including holomorphic and antiholomorphic collinear limits. This in turn implies that they give the correct Smatrix of the theory. Contents
with a Giant Fuzzy Moose
, 2001
"... We argue that the worldvolume theories of Dbranes probing orbifolds with discrete torsion develop, in the large quiver limit, new noncommutative directions. This provides an explicit ‘deconstruction ’ of a wide class of noncommutative theories. This also provides insight into the physical meaning ..."
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We argue that the worldvolume theories of Dbranes probing orbifolds with discrete torsion develop, in the large quiver limit, new noncommutative directions. This provides an explicit ‘deconstruction ’ of a wide class of noncommutative theories. This also provides insight into the physical meaning of discrete torsion and its relation to the Tdual B field. We demonstrate that the strict large quiver limit reproduces the matrix theory construction of higherdimensional Dbranes, and argue that finite ‘fuzzy moose ’ theories provide novel regularizations of noncommutative theories and explicit string theory realizations of gauge theories on fuzzy tori. We also comment briefly on the relation to NCOS, (2,0) and little string theories.
Lab/UFRHEP0504/GNPHE/0504/VACBT/0504 Superstring Theory on pp Waves
, 2008
"... We study the BMN correspondence between certain Penrose limits of type IIB superstrings on ppwave orbifolds with ADE geometries, and the set of fourdimensional N = 2 superconformal field theories constructed as quiver gauge models classified by finite ADE Lie algebras and affine ÂDE KacMoody alge ..."
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We study the BMN correspondence between certain Penrose limits of type IIB superstrings on ppwave orbifolds with ADE geometries, and the set of fourdimensional N = 2 superconformal field theories constructed as quiver gauge models classified by finite ADE Lie algebras and affine ÂDE KacMoody algebras. These models have 16 preserved supercharges and are based on systems of D3branes and wrapped D5 and D7branes. We derive explicitly the metrics of these ppwave orbifolds and show that the BMN extension requires, in addition to D5D5 open strings in bifundamental representations, D5D7 open strings involving orientifolds with Sp(N) gauge symmetry. We also give the correspondence rule between leading string states and gaugeinvariant operators in the N = 2 quiver gauge models. Keywords: Superstring theory, AdS/CFT correspondence, pp waves, ADE orbifolds, toric
ILL(TH)0008 hepth/0012050 Dbranes on Singularities: New Quivers from Old
, 2008
"... In this paper we present simplifying techniques which allow one to compute the quiver diagrams for various Dbranes at (nonAbelian) orbifold singularities with and without discrete torsion. The main idea behind the construction is to take the orbifold of an orbifold. Many interesting discrete group ..."
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In this paper we present simplifying techniques which allow one to compute the quiver diagrams for various Dbranes at (nonAbelian) orbifold singularities with and without discrete torsion. The main idea behind the construction is to take the orbifold of an orbifold. Many interesting discrete groups fit into an exact sequence N → G → G/N. As such, the orbifold M/G is easier to compute as (M/N)/(G/N) and we present graphical rules which allow fast computation given the M/N quiver.
3 authors, including:
, 2008
"... All intext references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. ..."
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All intext references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.