6 S ep 2 00 9 Positivity of Thom polynomials II : the Lagrange singularities
نویسندگان
چکیده
We study Thom polynomials associated with Lagrange singularities. We expand them in the basis of Q̃-functions. This basis plays a key role in the Schubert calculus of isotropic Grassmannians. We prove that the Q̃-function expansions of Thom polynomials of Lagrange singularities have always nonnegative coefficients. This is an analog of a result on Thom polynomials of mapping singularities and Schur Sfunctions, established formerly by the two last authors.
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