We report on extensive elastic neutron scattering to determine the wave vector of the magnetic order in CeCu6−xAux single crystals for x > 0.1. For all values of x investigated (0.2, 0.3, 0.5, 1.0) we find long-range incommensurate antiferromagnetic order with an ordering vector Q ≈ (0.625 0 0.275) for x = 0.2, nearly unchanged for x = 0.3, and Q ≈ (0.59 0 0) for x = 0.5, staying roughly the sa...

We consider two-dimensional $q$-state quantum clock models with fluctuations connecting states all-to-all transitions different choices for the matrix elements. study phase in these using Monte Carlo simulations and finite-size scaling, aim of characterizing crossover from emergent U(1) symmetry at transition (for $q\ensuremath{\ge}4$) to ${Z}_{q}$ ordered state. also classical three-dimensiona...

We determine the interface free energy Fo.d. between disordered and ordered phases in the q=10 and q=20 2-d Potts models using the results of multicanonical Monte Carlo simulations on L lattices, and suitable finite volume estimators. Our results, when extrapolated to the infinite volume limit, agree to high precision with recent analytical calculations. At the transition point βt the probabili...

Abstract: We demonstrate that a strongly exceptional collection on a singular toric surface can be used to derive the gauge theory on a stack of D3-branes probing the Calabi-Yau singularity caused by the surface shrinking to zero size. A strongly exceptional collection, i.e., an ordered set of sheaves satisfying special mapping properties, gives a convenient basis of D-branes. We find such coll...

We prove the following theorem: For a partially ordered set Q such that every countable subset has a strict upper bound, there is a forcing notion satisfying ccc such that, in the forcing model, there is a basis of the null ideal of the real line which is order-isomorphic to Q with respect to set-inclusion. This is a variation of Hechler’s classical result in the theory of forcing, and the stat...

We consider the following class of nonlinear singular differential equation − p x y′ x ′ q x f x, y x , p x y′ x 0, 0 < x < 1 subject to the Neumann boundary condition y′ 0 y′ 1 0. Conditions on p x and q x ensure that x 0 is a singular point of limit circle type. A simple approximation scheme which is iterative in nature is considered. The initial iterates are upper and lower solutions which c...

We prove the following theorem: For a partially ordered set Q such that every countable subset has a strict upper bound, there is a forcing notion satisfying ccc such that, in the forcing model, there is a basis of the null ideal of the real line which is order-isomorphic to Q with respect to set-inclusion. This is a variation of Hechler’s classical result in the theory of forcing, and the stat...

Wetting may occur when three or more phases (A, B, C,...) coexist. It consists of the appearance of a thick (macroscopic) layer of the C phase at an interface between the A and the B phases. This phenomenon has been observed experimentally and in computer simulation (for a review, see Ref. 1). It has also been investigated by mean field theory ~2 4) and by lowtemperature expansions. (s'6) In th...

We generalize the notion of "ground states" in the Pirogov-Sinai theory of first order phase transitions at low temperatures, applicable to lattice systems with a finite number of periodic ground states to that of "restricted ensembles" with equal free energies. A restricted ensemble is a Gibbs ensemble, i.e. equilibrium probability measure, on a restricted set of configurations in the phase sp...

Sum rules for electron proton total cross sections are deduced from the vanishing of various equal time commutators; it is shown how these cross sections determine the (spin-averaged) proton expectation value of all equal time commutators of components of the electric current and time derivatives thereof. (to be submitted to Phys. Rev. Letters) * Work supported by the U. S. Atomic Energy Commis...