2,354 research outputs found
Frobenius manifolds, Integrable Hierarchies and Minimal Liouville Gravity
We use the connection between the Frobrenius manifold and the Douglas string
equation to further investigate Minimal Liouville gravity. We search a solution
of the Douglas string equation and simultaneously a proper transformation from
the KdV to the Liouville frame which ensure the fulfilment of the conformal and
fusion selection rules. We find that the desired solution of the string
equation has explicit and simple form in the flat coordinates on the Frobenious
manifold in the general case of (p,q) Minimal Liouville gravity.Comment: 17 pages; v2: typos removed, some comments added, minor correction
Galois Groups in Rational Conformal Field Theory
It was established before that fusion rings in a rational conformal field
theory (RCFT) can be described as rings of polynomials, with integer
coefficients, modulo some relations. We use the Galois group of these relations
to obtain a local set of equation for the points of the fusion variety. These
equations are sufficient to classify all the RCFT, Galois group by Galois
group. It is shown that the Galois group is equivalent to the pseudo RCFT
group. We prove that the Galois groups encountered in RCFT are all abelian,
implying solvability by radicals of the modular matrix.Comment: 24 pages. Typos correcte
Stripes in thin ferromagnetic films with out-of-plane anisotropy
We examine the T=0 phase diagram of a thin ferromagnetic film with a strong
out-of-plane anisotropy in the vicinity of the reorientation phase transition
(with Co on Pt as an example). The phase diagram in the anisotropy-applied
field plane is universal in the limit where the film thickness is the shortest
length scale. It contains uniform fully magnetized and canted phases, as well
as periodically nonuniform states: a weakly modulated spin-density wave and
strongly modulated stripes. We determine the boundaries of metastability of
these phases and point out the existence of a critical point at which the
difference between the SDW and stripes vanishes. Out-of-plane magnetization
curves exhibit a variety of hysteresis loops caused by the coexistence of one
or more phases. Additionally, we study the effect of a system edge on the
orientation of stripes. We compare our results with recent experiments.Comment: added references and clarified derivations in response to referee
comment
Comment on ``Magnon wave forms in the presence of a soliton in two--dimensional antiferromagnets with a staggered field''
Very recently Fonseca and Pires [Phys. Rev. B 73, 012403(2006)] have studied
the soliton--magnon scattering for the isotropic antiferromagnet and calculated
``exact'' phase shifts, which were compared with the ones obtained by the Born
approximation. In this Comment we correct both the soliton and magnon solutions
and point out the way how to study correctly the scattering problem.Comment: 2 pages (RevTeX
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