q-deformed su(2|2) boundary S-matrices via the ZF algebra

Beisert and Koroteev have recently found a bulk S-matrix corresponding to a q-deformation of the centrally-extended su(2|2) algebra of AdS/CFT. We formulate the associated Zamolodchikov-Faddeev algebra, using which we derive factorizable boundary S-matrices that generalize those of Hofman and Maldacena.Comment: 15 pages; v2: correct misplaced equation labe

Boundary energy of the open XXZ chain from new exact solutions

Bethe Ansatz solutions of the open spin-1/2 integrable XXZ quantum spin chain at roots of unity with nondiagonal boundary terms containing two free boundary parameters have recently been proposed. We use these solutions to compute the boundary energy (surface energy) in the thermodynamic limit.Comment: 20 pages, LaTeX; amssymb, 3 figure

Open-chain transfer matrices for AdS/CFT

We extend Sklyanin's construction of commuting open-chain transfer matrices to the SU(2|2) bulk and boundary S-matrices of AdS/CFT. Using the graded version of the S-matrices leads to a transfer matrix of particularly simple form. We also find an SU(1|1) boundary S-matrix which has one free boundary parameter.Comment: 11 pages; v2: reference adde

Boundary energy of the general open XXZ chain at roots of unity

We have recently proposed a Bethe Ansatz solution of the open spin-1/2 XXZ quantum spin chain with general integrable boundary terms (containing six free boundary parameters) at roots of unity. We use this solution, together with an appropriate string hypothesis, to compute the boundary energy of the chain in the thermodynamic limit.Comment: 22 pages, 6 figures; v2: some comments, a reference and a footnote adde