15 research outputs found
A finite Toda representation of the box-ball system with box capacity
A connection between the finite ultradiscrete Toda lattice and the box-ball
system is extended to the case where each box has own capacity and a carrier
has a capacity parameter depending on time. In order to consider this
connection, new carrier rules "size limit for solitons" and "recovery of
balls", and a concept "expansion map" are introduced. A particular solution to
the extended system of a special case is also presented.Comment: 20 pages, 9 figure
The A^{(1)}_M automata related to crystals of symmetric tensors
A soliton cellular automaton associated with crystals of symmetric tensor
representations of the quantum affine algebra U'_q(A^{(1)}_M) is introduced. It
is a crystal theoretic formulation of the generalized box-ball system in which
capacities of boxes and carriers are arbitrary and inhomogeneous. Scattering
matrices of two solitons coincide with the combinatorial R matrices of
U'_q(A^{(1)}_{M-1}). A piecewise linear evolution equation of the automaton is
identified with an ultradiscrete limit of the nonautonomous discrete KP
equation. A class of N soliton solutions is obtained through the
ultradiscretization of soliton solutions of the latter.Comment: 45 pages, latex2e, 2 figure
A systematic method for constructing time discretizations of integrable lattice systems: local equations of motion
We propose a new method for discretizing the time variable in integrable
lattice systems while maintaining the locality of the equations of motion. The
method is based on the zero-curvature (Lax pair) representation and the
lowest-order "conservation laws". In contrast to the pioneering work of
Ablowitz and Ladik, our method allows the auxiliary dependent variables
appearing in the stage of time discretization to be expressed locally in terms
of the original dependent variables. The time-discretized lattice systems have
the same set of conserved quantities and the same structures of the solutions
as the continuous-time lattice systems; only the time evolution of the
parameters in the solutions that correspond to the angle variables is
discretized. The effectiveness of our method is illustrated using examples such
as the Toda lattice, the Volterra lattice, the modified Volterra lattice, the
Ablowitz-Ladik lattice (an integrable semi-discrete nonlinear Schroedinger
system), and the lattice Heisenberg ferromagnet model. For the Volterra lattice
and modified Volterra lattice, we also present their ultradiscrete analogues.Comment: 61 pages; (v2)(v3) many minor correction
Tropical Krichever construction for the non-periodic box and ball system
A solution for an initial value problem of the box and ball system is
constructed from a solution of the periodic box and ball system. The
construction is done through a specific limiting process based on the theory of
tropical geometry. This method gives a tropical analogue of the Krichever
construction, which is an algebro-geometric method to construct exact solutions
to integrable systems, for the non-periodic system.Comment: 13 pages, 1 figur
Integrable structure of box-ball systems: crystal, Bethe ansatz, ultradiscretization and tropical geometry
The box-ball system is an integrable cellular automaton on one dimensional
lattice. It arises from either quantum or classical integrable systems by the
procedures called crystallization and ultradiscretization, respectively. The
double origin of the integrability has endowed the box-ball system with a
variety of aspects related to Yang-Baxter integrable models in statistical
mechanics, crystal base theory in quantum groups, combinatorial Bethe ansatz,
geometric crystals, classical theory of solitons, tau functions, inverse
scattering method, action-angle variables and invariant tori in completely
integrable systems, spectral curves, tropical geometry and so forth. In this
review article, we demonstrate these integrable structures of the box-ball
system and its generalizations based on the developments in the last two
decades.Comment: 73 page