120793216
The coherent state variational algorithm: A numerical method for solving large-N gauge theories
This paper presents a new approach for studying large-N gauge theories which directly exploits the classical nature of the N → ∞ limit. This method supplies a practical algorithm for computing and minimizing the classical hamiltonian (or effective action) which governs N = ∞ dynamics, and allows one to calculate physical quantities such as the mass spectrum or scattering amplitudes of glueballs or mesons. Two different implementations of the basic ideas are discussed; one variant provides an algorithm for constructing N = ∞ master field matrices, while the other works directly with a list of expectation values of physical operators. Algorithms are developed for both the hamiltonian and euclidean formulations of lattice gauge theories. The inclusion of fermions in the hamiltonian version is also described. Detailed tests of the method in the context of the exactly solvable one-plaquette model are presented.
17198705
Necessary and sufficient conditions for non-perturbative equivalences of large Nc orbifold gauge theories
Large N coherent state methods are used to study the relation between U(Nc) gauge theories containing adjoint representation matter fields and their orbifold projections. The classical dynamical systems which reproduce the large Nc limits of the quantum dynamics in parent and daughter orbifold theories are compared. We demonstrate that the large Nc dynamics of the parent theory, restricted to the subspace invariant under the orbifold projection symmetry, and the large Nc dynamics of the daughter theory, restricted to the untwisted sector invariant under ``theory space'' permutations, coincide. This implies equality, in the large Nc limit, between appropriately identified connected correlation functions in parent and daughter theories, provided the orbifold projection symmetry is not spontaneously broken in the parent theory and the theory space permutation symmetry is not spontaneously broken in the daughter. The necessity of these symmetry realization conditions for the validity of the large Nc equivalence is unsurprising, but demonstrating the sufficiency of these conditions is new. This work extends an earlier proof of non-perturbative large Nc equivalence which was only valid in the phase of the (lattice regularized) theories continuously connected to large mass and strong coupling [1].
118596387
Holographic realization of large-Nc orbifold equivalence with non-zero chemical potential
A bstractRecently, it has been suggested that large-Nc orbifold equivalences may be applicable to certain theories with chemical potentials, including QCD, in certain portions of their phase diagram. When valid, such an equivalence offers the possibility of relating large-Nc QCD at non-zero baryon chemical potential, a theory with a complex fermion determinant, to a related theory whose fermion determinant is real and positive. In this paper, we provide a test of this large Nc equivalence using a holographic realization of a supersymmetric theory with baryon chemical potential and a related theory with isospin chemical potential. We show that the two strongly-coupled, large-Nc theories are equivalent in a large region of the phase diagram.
122912012
Canonical treatment of «noncanonical» gauges for constrained Hamiltonian systems
118398444
Boost invariant flow, black hole formation, and far-from-equilibrium dynamics in N = 4 supersymmetric Yang-Mills theory
Using gauge/gravity duality, we study the creation and evolution of boost-invariant anisotropic, strongly-coupled N=4 supersymmetric Yang-Mills plasma. In the dual gravitational description, this corresponds to horizon formation in a geometry driven to be anisotropic by a time-dependent change in boundary conditions.
125172147
THE INSTABILITY OF HOT FLAT SPACE
120315024
CROSS SECTIONS FOR THE PRODUCTION OF Cl, K, Ca, AND Sc ISOTOPES IN THE BOMBARDMENT OF Pb AND U WITH 3.0-Bev PROTONS
Cross sections for the formation of some nuclides in the mass number range 38 to 48 in the bombardment of Pb and U with 3.0-Bev protons were measured. The maximum of the isobaric yield distributions for the nuclides from the Pb bombardnnent occurs at the stability line, while that from U is somewhat on the neutron-excess side. Total cross sections of 4 to 5 mb per mass number are deduced from the Pb data leading to a revision of the mass-yield curve in this region as proposed by Wolfgang et al.The cross sections from uranium are approximately twice as large as those from Pb. The data are shown to be consistent with a cascade-fission-evaporation mechanism. (auth)
120217954
( p , xn ) and ( p , pxn ) Reactions of Yttrium-89 with 5-85-MeV Protons