@article {IOPORT.05586493, author = {Inoue, Rei and Takenawa, Tomoyuki}, title = {A tropical analogue of Fay's trisecant identity and the ultra-discrete periodic Toda lattice.}, year = {2009}, journal = {Communications in Mathematical Physics}, volume = {289}, number = {3}, issn = {0010-3616}, pages = {995-1021}, publisher = {Springer-Verlag, Berlin}, doi = {10.1007/s00220-009-0815-3}, abstract = {Fay's trisecant identity for Riemann's theta function, associated with an algebraic curve, was established in [{\it J. D. Fay}, Theta functions on Riemann surfaces. Lecture Notes in Mathematics. 352. Berlin-Heidelberg-New York: Springer-Verlag (1973; Zbl 0281.30013)]. In the paper under review, the tropical version of this identity is established for certain special hyperelliptic tropical curves (and conjectured for an arbitrary tropical curve). In particular, the ultra-discrete periodic Toda lattice system $T$ can be transformed into a special case of Fay's trisecant identity for a tropical spectral curve of $T$, which allows the authors to obtain the general solution of $T$ in terms of the corresponding tropical Riemann's theta function.}, reviewer = {Alexander Esterov (Moscow)}, identifier = {05586493}, }