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Alexander Polishchuk

Publications and source records attributed to Alexander Polishchuk.

124 records · Page 7Linked to original sources

Classical Yang-Baxter equation and the $A_{\infty}$-constraint

We show that elliptic solutions of the classical Yang-Baxter equation can be obtained from triple Massey products on elliptic curve. We introduce the associative version of this equation which has two spectral parameters and construct its elliptic solutions. We also study some degenerations of these solutions.

math.AG↗

Categorical Mirror Symmetry: The Elliptic Curve

We describe an isomorphism of categories conjectured by Kontsevich. If $M$ and $\widetilde{M}$ are mirror pairs then the conjectural equivalence is between the derived category of coherent sheaves on $M$ and a suitable version of Fukaya's category of Lagrangian submanifolds on $\widetilde{M}.$ We prove this equivalence when $M$ is an elliptic curve and $\widetilde{M}$ is its dual curve, exhibiting the dictionary in detail.

math.AG↗

Fourier transform over finite field and identities between Gauss sums

This is a sequel to math.AG/0003009. Here we study identities for the Fourier transform of "elementary functions" over finite field containing "exponents" of monomial rational functions. It turns out that these identities are governed by monomial identities between Gauss sums. We show that similar to the case of complex numbers such identities correspond to linear relations between certain divisors on the space of multiplicative characters.

math.AG↗

Homological mirror symmetry with higher products

We construct an $A_{\infty}$-structure on the Ext-groups of hermitian holomorphic vector bundles on a compact complex manifold. We propose a generalization of the homological mirror conjecture due to Kontsevich. Namely, we conjecture that for mirror dual Calabi-Yau manifolds $M$ and $X$ there exists an $A_{\infty}$-functor from Fukaya's symplectic $A_{\infty}$-category of $M$ to the $A_{\infty}$-derived category of $X$ which is a homotopy equivalence on morphisms. We verify the part of this conjecture concering triple products for elliptic curves.

math.AG↗

Torelli theorem via Fourier-Mukai transform

We show that the Fourier transform on the Jacobian of a curve interchanges "$δ$ functions" at the curve and the theta divisor. The Torelli theorem is an immediate consequence.

math.AG↗

Generalized character sums associated to regular prehomogeneous vector spaces

In this paper we consider the analogue of the Sato's functional equation for the prehomogeneous vector spaces over finite fields. The corresponding character sums depend on a relative invariant on such a space and an irreducible representation of the group of components of the stabilizer of a generic point. The proof is based on the Picard-Lefschetz formula in $l$-adique cohomology.

math.AG↗

Massey and Fukaya products on elliptic curves

This note is a continuation of our paper with E. Zaslow "Categorical mirror symmetry: the elliptic curve", math.AG/9801119. We compare some triple Massey products on elliptic curve with the corresponding Fukaya products on the symplectic torus and recover the classical identity due to Kronecker. We also compute some triple Fukaya products such that the corresponding Massey products are not correctly defined.

math.AG↗

Fukaya category and Fourier transform

We construct a version of Fourier transform for families of real tori. This transform defines a functor from certain category associated with a symplectic family of tori to the category of holomorphic vector bundles on the dual family (the dual family has a natural complex structure). In the 1-dimensional case the former category is closely related to the Fukaya category.

math.AG↗

Fourier transform for D-algebras

We construct a version of Fourier transform for a class of non-commutative algebras over abelian varieties which include algebras of twisted differential operators generalizing the previous construction of Laumon (alg-geom/9603004) and of the second author (alg-geom/9602023). We also construct the microlocal version of this transform and its etale localization in the framework of Kapranov's theory of NC-schemes (see math.AG/9802041).

math.AG↗

M. P. Appell's function and vector bundles of rank 2 on elliptic curve

This paper is devoted to the function introduced by M. P. Appell in connection with decomposition of elliptic functions of the third kind into simple elements. We show that this function (which appeared as a Fukaya triple product in math.AG/9803017) is related to global sections of rank-2 vector bundles on elliptic curves. We derive analogues of theta-identities for this function and prove the divisibility property for the action of modular group which should be considered as a replacement for functional equation.

math.AG↗

Kazhdan-Laumon representations of finite Chevalley groups, character sheaves and some generalization of the Lefschetz-Verdeier trace formula

In this paper we investigate the representations of reductive groups over a finite field, introduced in 1987 by D.Kazhdan and G.Laumon. We show that generically these representations are irreducible and that their character is equal to the function obtained by traces of Frobenius morphism on the stalks of the corresponding Lusztig's character sheaf. This, together with the corresponding result by G.Lusztig, implies that generic Kazhdan-Laumon representations are isomorphic to the corresponding Deligne-Lusztig representations. In the second half of the paper we give a direct geometric construction of this isomorphism, assuming that certain generalization of the Lefschetz-Verdier trace formula holds.

math.AG↗

Analogue of Weil representation for abelian schemes

In this paper we construct a projective action of certain arithmetic group on the derived category of coherent sheaves on an abelian scheme $A$, which is analogous to Weil representation of the symplectic group. More precisely, the arithmetic group in question is a congruence subgroup in the group of "symplectic" automorphisms of $A\times\hat{A}$ where $\hat{A}$ is the dual abelian scheme. The "projectivity" of this action refers to shifts in the derived category and tensorings with line bundles pulled from the base. In particular, if $A$ is an abelian scheme over $S$ equipped with an ample line bundle $L$ of degree 1 then we construct an action of a central extension of $Sp_{2n}(\Bbb Z)$ by $\Bbb Z\times Pic(S)$ on the derived category of coherent sheaves on $A^n$ (the $n$-th fibered power of $A$ over $S$). We describe the corresponding central extension explicitly using the the canonical torsion line bundle on $S$ associated with $L$. As a main technical result we prove the existence of a representation of rank $d$ for a symmetric finite Heisenberg group scheme of odd order $d^2$.

alg-geom↗

Determinant bundles for abelian schemes

To a symmetric, relatively ample line bundle on an abelian scheme one can associate a linear combination of the determinant bundle and the relative canonical bundle, which is a torsion element in the Picard group of the base. We improve the bound on the order of this element found by Faltings and Chai. In particular, we obtain an optimal bound when the degree of the line bundle d is odd and the set of residue characteristics of the base does not intersect the set of primes p dividing d, such that $p\equiv -1\mod(4)$ and p<2g, where g is the relative dimension of the abelian scheme. Also, we show that in some cases these torsion elements generate the entire torsion subgroup in the Picard group of the corresponding moduli stack.

alg-geom↗