Moduli of Prym curves.
We prove a conjecture due to Goncharov and Manin which states that the periods of the moduli spaces of Riemann spheres with marked points are multiple zeta values. We do this by introducing a differential algebra of multiple polylogarithms on and proving that it is closed under the operation of taking primitives. The main idea is to apply a version of Stokes’ formula iteratively to reduce each period integral to multiple zeta values. We also give a geometric interpretation of the double shuffle...
We study the Hilbert scheme of smooth connected curves on a smooth del Pezzo -fold . We prove that any degenerate curve , i.e. any curve contained in a smooth hyperplane section of , does not deform to a non-degenerate curve if the following two conditions are satisfied: (i) and (ii) for every line on such that , the normal bundle is trivial (i.e. ). As a consequence, we prove an analogue (for ) of a conjecture of J. O. Kleppe, which is concerned with non-reduced components...