Flag Varieties and the Yang-Baxter Equation

We investigate certain bases of Hecke algebras defined by means of theYang–Baxter equation, which we call Yang–Baxter bases. These bases areessentially self-adjoint with respect to a canonical bilinear form. In thecase of the degenerate Hecke algebra, we identify the coefficients in theexpansion of the Yang–Baxter basis on the usual basis of the algebra withspecializations of double Schubert polynomials. We also describe theexpansions associated to other specializations of the generic Heckealgebra.     

LOW TEMPERATURE ABSORPTION SPECTRUM STUDIES: LIGHT-INDUCED PIGMENT CHANGES IN PORPHYRIDIUM CULTURES

Abstract— A single-beam spectrophotometer with a low-temperature sample chamber has been built. An automatic mechanical device gives a suitable baseline and allows very reproducible absorption spectra to be obtained. The red alga Porphyridium grown, during a few days, under high-intensity monochromatic light, showed a decrease in the amount of chlorophyll a forms directly or indirectly excited. Furthermore, a 585 nm absorption band is observed in red algae such as Porphyridium, Rhodymenia and Calliblepharis. This 585 nm band is labile to many damaging agents.