T. Deguchi,  Ochanomizu University,

Title: Correlation functions of the integrable higher-spin XXZ spin chain  

Abstract: Correlation functions of the spin-1/2 XXZ spin chain, i.e. the
density matrices of the spin chain, have attracted much interest in physics
and mathematics during the last decades. 
In this talk, we show multiple-integral representations for the
zero-temperature correlation functions of the integrable spin-s XXZ spin
chain for a region in the massless regime [1,2]. In particular, we express
the multiple-integral representation for the spin-s XXZ correlation function
of any given product of elementary matrices in the form of a single product
of multiple integrals. We derive the correlation functions by the algebraic
Bethe ansatz method based on the study of the ground-state 2s-string
solutions of the spin-s XXZ spin chain. Here we also make an extensive use
of the representation theory of the affine quantum group [1,2,3]. 


[1] T. Deguchi and C. Matsui, Nucl. Phys. B Vol. 814 (2009) 405-438. 

[2] T. Deguchi and C. Matsui, Correlation functions of the integrable
higher-spin XXX and XXZ spin chains through the fusion method,
arXiv:0907.0582v3.  

[3] T. Deguchi and K. Motegi, Integrable quantum spin-chain Hamiltonians 
and solvable transfer matrices constructed as Hermitian operators through 
the affine quantum group of sl(2), in preparation.