arXiv subjects

A. G. Gorinov

Publications and source records attributed to A. G. Gorinov.

5 recordsLinked to original sources

arXiv2023

Conical resolutions and cohomology of the moduli spaces of nodal hypersurfaces

A projective hypersurface is nodal if it does not have singularities worse than simple nodes. We calculate the rational cohomology of the spaces of equations of nodal cubic and quartic plane curves and also nodal cubic surfaces in the projective 3-space. We deduce the cohomology of the corresponding spaces of equations and moduli spaces. In the case of plane cubics we use the method of conical resolutions. We handle plane quartics by applying a more general version of this method which we construct in this paper. For cubic surfaces we use an explicit description of the compact GIT quotient.

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arXiv2020

A purity theorem for configuration spaces of smooth compact algebraic varieties

B. Totaro showed \cite{totaro} that the rational cohomology of configuration spaces of smooth complex projective varieties is isomorphic as an algebra to the $E_2$ term of the Leray spectral sequence corresponding to the open embedding of the configuration space into the Cartesian power. In this note we show that the isomorphism can be chosen to be compatible with the mixed Hodge structures. In particular, we prove that the mixed Hodge structures on the configuration spaces of smooth complex projective varieties are direct sums of pure Hodge structures.

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arXiv2017

Two-sided fundamental theorem of affine geometry

The fundamental theorem of affine geometry says that a self-bijection $f$ of a finite-dimensional affine space over a possibly skew field takes left affine subspaces to left affine subspaces of the same dimension, then $f$ of the expected type, namely $f$ is a composition of an affine map and an automorphism of the field. We prove a two-sided analogue of this: namely, we consider self-bijections as above which take affine subspaces affine subspaces but which are allowed to take left subspaces to right ones and vice versa. We show that these maps again are of the expected type.

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arXiv2013

Division theorems for the rational cohomology of discriminant complements and applications to automorphism groups in finite characteristic

In this note we extend some of the results of a previous paper \url{arXiv:math/0511593} to algebraically closed fields of finite characteristic. In particular, we show that there is an explicit expression in $n$ and $d$ which is divisible by the prime to $p$ part of the order of the the automorphism group of a smooth degree $d$ hypersurface $\subset \mathbb{P}^n_k$ for $k$ an algebraically closed field of characteristic $p$.

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arXiv2006

On the cobordisms of Möbius circles

The boundary of a Möbius manifold carries a canonical Möbius structure. This enables one to define the cobordism group of $n$-dimensional (closed) Möbius manifolds. The purpose of this note is to show that the cobordism group of Möbius circles is zero, i.e., every Möbius circle bounds a Möbius surface. We also complete N. Kuiper's classification of projective structures on $S^1$ (we show that there are in fact two series of projective circles with parabolic holonomy, and not one).

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