M ar 2 00 3 COMBINATORIAL CLASSES ON M g , n ARE TAUTOLOGICAL
نویسنده
چکیده
The combinatorial description via ribbon graphs of the moduli space of Riemann surfaces allows to define combinatorial cycles in a natural way. Witten and Kontsevich first conjectured that these classes are polynomials in the tautological classes. We answer affirmatively to this conjecture and find recursively all the polynomials. Moreover we lift the combinatorial classes to the Deligne-Mumford compactification of the moduli space and we give a partial answer to the same problem in this context.
منابع مشابه
2 00 4 COMBINATORIAL CLASSES ON M g , n ARE
The combinatorial description via ribbon graphs of the moduli space of Riemann surfaces makes it possible to define combinatorial cycles in a natural way. Witten and Kontsevich first conjectured that these classes are polynomials in the tautological classes. We answer affirmatively to this conjecture and find recursively all the polynomials.
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