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Tomohide Terasoma

Publications and source records attributed to Tomohide Terasoma.

34 records · Page 2Linked to original sources

Algebraic correspondences between genus three curves and certain Calabi-Yau varieties

In this paper, we construct certain algebraic correspondences between genus three curves and certain type of Calabi-Yau threefolds which is double coverings of three dimensional projective space. Via this correspondences, the first cohomology groups of the curves can be embedded into the third cohomology groups of the Calabi-Yau three folds. Moreover we prove that the cokernel of this inclusion of variations ofHodge structures can not be a factor of any variations of Hodge structures comming from polarized abelian schemes.

math.AG↗

Arithmetic-geometric means for hyperelliptic curves and Calabi-Yau varieties

In this paper, we define a generalized arithmetic-geometric mean $μ_g$ among $2^g$ terms motivated by $2τ$-formulas of theta constants. By using Thomae's formula, we give two expressions of $μ_g$ when initial terms satisfy some conditions. One is given in terms of period integrals of a hyperelliptic curve $C$ of genus $g$. The other is by a period integral of a certain Calabi-Yau $g$-fold given as a double cover of the $g$-dimensional projective space $\mathbf{P}^g$.

math.AG↗

The Artin-Schreier DGA and the F_p fundamental group of an F_p scheme

In this paper, we proved that the F_p completioin of fundamental group of an F_p shceme can be computed by the bar complex of Artien-Schreier differential graded algebra. Artin-Schreier differential graded algebra is obtained by a relation diagram of identity map and frobenius map by Kats' theorem.

math.AG↗

DG-category and simplicial bar complex

In this paper, we prove that the DG category of DG complex of DG category of a differential graded algebra A is homotopy equivalent to that of comodules over the simplicial bar complex of A. Under the assuption of connectedness of A, we show the homotopy category of A-connection is equivalent to comodules on the homology of bar complex. As an application, we construct coalgebras classifying nilpotent variation of mixed Tate Hodge structures on algebraic varieties.

math.AG↗

Period map of a certain K3 family with an S5-action

In this paper, we study the period map of a certain one-parameter family of quartic K3 surfaces with an S5-action. We construct automorphic forms on the period domain as the pull-backs of theta constants of genus 2 by a modular embedding. Using these automorphic forms, we give an explicit presentation of the inverse period map.

math.AG↗

Rational convex cones and cyclotomic multiple zeta values

In this paper, we introduce zeta values of rational convex cones, which is a generalization of cyclotomic multiple zeta values. These zeta values have integral expressions. The main theorem asserts that zeta values of cones can be expressed as linear combinations of cyclotomic multiple zeta values over some cyclotomic field.

math.AG↗

Algebraicity of cyclotomic Weil Hodge cycles

Please forget our result!! I would like to apologize that there are a fatal mistake in the proof of the algebraicity of Weil Hodge cycles. See contents for the reason. So please forget about the result of algebraicity.

math.AG↗

Mixed Tate Motives and Multiple Zeta Values

In this paper, we construct an object of the abelian category of mixed Tate motive associated to multiple zeta values. as a consequence, we prove the inequality of the dimension of the vector space generated by multiple zeta values, which is conjectured by Zagier. (Some errors was corrected from the first version. Namely, we changed the definition of the boundary $\bold B^0$.)

math.AG↗

Convolution theorem for non-degenerate maps and composite singularities

We give a formula for the spectral pairs (after Steenbrink) for composite singularities of several variables. (Note that for two variable case is studyed by Nemethi-Steenbrink.) Here composite singularity is given by the equation f(g_1, ..., g_n) = 0. For technical reason, we assume that f is non-degenerated with respect to the Newton boundary.

math.AG↗

Monodromy weight filtration is independent of l

In this paper, we prove the l-independence of monodromy weight filtration for a geometrically smooth variety over an equicharacteristic local field. We also prove the l-independence for the geometric monodromy representation on the associated graded module of weight monodromy filtration.

math.AG↗

Degeneration of curves and analytic deformation

Let C_1 and C_2 be two degenerations of genus g curves. We prove that if two degenerations defines the same conjugacy classes in the mapping class group, they are equivalent under analytic deformations.

math.AG↗

Hodge and Tate conjectures for hypergeometric sheaves

A constructible sheaf corresponding to Gel'fand Zelevinski hypergeometric functions on a torus is called hypergeometric sheaf. We consider Hodge and Tate conjectrue for hypergeomtric sheaves. Hodge conjecture is formulated in terms of variation of Hodge strucure and Tate conjecture is done for l-adic sheaves on an open set of torus. We prove Hodge and Tate conjecture up to Hodge and Tate cycle of Fermat motifes. We use cohomological Mellin transform to get the main theorem. This is the final revision for preprint.

alg-geom↗

Determinant of Period Integral

Period integrals arise from the comparison between Betti cohomologies and de Rham cohomologies. In this paper, we give a formula for the determinant of period integrals in terms of the canonical pairing between Picard group of rank 1 realizations and relative Chow group. It is compatible with the similar formula for Galois modules proved by the first author, and as a consequence, under the assumption of Gersten resolution, the determinant of the cohomology of a determinantally motivic object is motivic.

alg-geom↗

Schur-Weyl Reciprocity for the Hecke Algebra of $(\Bbb Z/r\Bbb Z)\wr \frak S_n$

The purpose of this paper is to give a reciprocity between $U_q(h)$ and $\Cal H_{n,r}$, the Hecke algebra of $(\Bbb Z / r\Bbb Z)\wr \frak S_n$ introduced by Ariki and Koike. Let $K=\Bbb Q(q,u_1,\dots ,u_r)$ be the field of rational funcitons in variables $q,u_1,\dots ,u_r$. We adopt $K$ as the base field for both the quantized universal enveloping algebra $U_q(gl_r)$ and the Hecke algebra $\Cal H_n$. We denote by $U_q(h)$ the $K$-subalgebra of $U_q(gl_r)$ generated by $q^{E_{ii}}\;$'s $(1\le i \le r)$. In this paper, we show that the commutant of $U_q(h)$ in $End((K^r)^{\otimes n})$ is isomorphic to a quotient of $\Cal H_{n,r}$. We also determine the irreducible decomposition of $(K^r)^{\otimes n}$ under the action of $\Cal H_{n,r}$. As a consequence, we obtain the reciprocity for $U_q(h)$ and $\Cal H_{n,r}$.

hep-th↗