Abstract：

From the work of S.P. Novikov’s school in 1960s it was known that the logarithm of the formal group in complex cobordisms can be written explicitly in terms of the complex projective spaces, but the algebro-geometric nature of the coefficients of the corresponding exponential was not clear until recently. In the talk I will explain that the answer can be given by the smooth theta divisors of principally polarised abelian varieties. We will see also interesting relations between the theta divisors, permutohedral varieties and Tomei manifolds from the integrable Toda lattice theory. The talk is based on joint works with V.M. Buchstaber.