54 research outputs found
Ising Spin Glasses on Wheatstone-Bridge Hierarchical Lattices
Nearest-neighbor-interaction Ising spin glasses are studied on three
different hierarchical lattices, all of them belonging to the Wheatstone-Bridge
family. It is shown that the spin-glass lower critical dimension in these
lattices should be greater than 2.32. Finite-temperature spin-glass phases are
found for a lattice of fractal dimension (whose unit cell is
obtained from a simple construction of a part of the cubic lattice), as well as
for a lattice of fractal dimension close to five.Comment: Accepted for publication in Physics Letters
Solutions of the Polchinski ERG equation in the O(N) scalar model
Solutions of the Polchinski exact renormalization group equation in the
scalar O(N) theory are studied. Families of regular solutions are found and
their relation with fixed points of the theory is established. Special
attention is devoted to the limit , where many properties can be
analyzed analytically.Comment: 34 pages, 10 figures. References added. Version accepted for
publication in the International Journal of Modern Physics
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