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Related papers: Modified Derksen invariant

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The Konno invariant of a projective variety X is the minimum geometric genus of the fiber of a rational pencil on X. It was computed by Konno for surfaces in P^3, and in general can be viewed as a measure of the complexity of X. We estimate…

Algebraic Geometry · Mathematics 2018-08-14 Lawrence Ein , Robert Lazarsfeld

Using the method of moving frames we analyze the algebra of differential invariants for surfaces in three-dimensional affine geometry. For elliptic, hyperbolic, and parabolic points, we show that if the algebra of differential invariants is…

Mathematical Physics · Physics 2021-04-15 Örn Arnaldsson , Francis Valiquette

Using the $\sharp$-minimal model program of uniruled varieties we show that for any pair $(X, \H)$ consisting of a reduced and irreducible variety $X$ of dimension $k \geq 3$ and a globally generated big line bundle $\H$ on $X$ with $d:=…

Algebraic Geometry · Mathematics 2007-05-23 A. L. Knutsen , C. Novelli , A. Sarti

The dual variety X* for a smooth n-dimensional variety X of the projective space P^N is the set of tangent hyperplanes to X. In the general case, the variety X* is a hypersurface in the dual space (P^N)*. If dim X* < N - 1, then the variety…

Differential Geometry · Mathematics 2007-05-23 Maks A. Akivis , Vladislav V. Goldberg

We construct indecomposable and noncrossed product division algebras over function fields of smooth curves X over Z_p. This is done by defining an index preserving morphism s:Br(\hat K(X))' -> Br(K(X))' which splits res:Br(K(X)) -> Br(\hat…

Rings and Algebras · Mathematics 2010-11-24 Eric Brussel , Kelly McKinnie , Eduardo Tengan

We study varieties $X \subset P^r$ such that is $N_X^*(k)$ is an Ulrich vector bundle for some integer $k$. We first prove that such an $X$ must be a curve. Then we give several examples of curves with $N_X^*(k)$ an Ulrich vector bundle.

Algebraic Geometry · Mathematics 2024-06-11 Vincenzo Antonelli , Gianfranco Casnati , Angelo Felice Lopez , Debaditya Raychaudhury

A simple method of constructing a big stock of algebraic varieties with trivial Makar-Limanov invariant is described, the Derksen invariant of some varieties is computed, the generalizations of the Makar-Limanov and Derksen invariants are…

Algebraic Geometry · Mathematics 2011-10-26 Vladimir L. Popov

In this paper, we give an example of a finitely generated 3-dimensional C-algebra which has infinitely generated Derksen invariant as well as Makar-Limaonv invariant.

Algebraic Geometry · Mathematics 2007-06-29 Stefan Maubach

We develop the theory of derived differential geometry in terms of bundles of curved $L_\infty[1]$-algebras, i.e. dg manifolds of positive amplitudes. We prove the category of derived manifolds is a category of fibrant objects. Therefore,…

Differential Geometry · Mathematics 2021-06-15 Kai Behrend , Hsuan-Yi Liao , Ping Xu

We prove that any nonconstant entire holomorphic curve from the complex line C into a projective algebraic hypersurface X = X^n in P^{n+1}(C) of arbitrary dimension n (at least 2) must be algebraically degenerate provided X is generic if…

Algebraic Geometry · Mathematics 2017-04-04 Simone Diverio , Joel Merker , Erwan Rousseau

We give an infinite dimensional description of the differential K-theory of a manifold $M$. The generators are triples $[H, A, \omega]$ where $H$ is a ${\bf Z}_2$-graded Hilbert bundle on $M$, $A$ is a superconnection on $H$ and $\omega$ is…

Differential Geometry · Mathematics 2018-01-29 Alexander Gorokhovsky , John Lott

We consider an action of a compact group whose dual is archimedean linearly ordered or a direct product (or sum) of such groups on a von Neumann algebra, M. We define the generalized Hardy subspace of the Hilbert space of a standard…

Operator Algebras · Mathematics 2020-10-13 Costel Peligrad

We prove the unrolled superalgebra $\mathcal{U}_{\xi}^{H}\mathfrak{sl}(2|1)$ has a completion which is a ribbon superalgebra in a topological sense where $\xi$ is a root of unity of odd order. Using this ribbon superalgebra we construct its…

Quantum Algebra · Mathematics 2018-06-22 Ngoc Phu Ha

We consider positive semidefinite kernels valued in the $*$-algebra of continuous and continuously adjointable operators on a VH-space (Vector Hilbert space in the sense of Loynes) and that are invariant under actions of $*$-semigroups. For…

Operator Algebras · Mathematics 2025-11-04 Serdar Ay , Aurelian Gheondea

We construct the crossed product of a C(X)-algebra by an endomorphism, in such a way that the endomorphism itself becomes induced by the bimodule of continuous sections of a vector bundle. Some motivating examples for such a construction…

Operator Algebras · Mathematics 2011-11-21 Ezio Vasselli

We consider weakly positive semidefinite kernels valued in ordered $*$-spaces with or without certain topological properties, and investigate their linearisations (Kolmogorov decompositions) as well as their reproducing kernel spaces. The…

Functional Analysis · Mathematics 2025-11-04 Serdar Ay , Aurelian Gheondea

If A is a graded connected algebra then we define a new invariant, polydepth A, which is finite if $Ext_A^*(M,A) \neq 0$ for some A-module M of at most polynomial growth. Theorem 1: If f : X \to Y is a continuous map of finite category, and…

Algebraic Topology · Mathematics 2007-05-23 Y. Felix , S. Halperin , J. -C. Thomas

Inspired by the work [Ra1], we directly give a complete classification of irreducible calibrated representations of affine Yokonuma-Hecke algebras $\widehat{Y}_{r,n}(q)$ over $\mathbb{C},$ which are indexed by $r$-tuples of placed skew…

Representation Theory · Mathematics 2016-09-30 Weideng Cui

We construct a family of exact functors from the BGG category of representations of the Lie algebra sl to the category of finite-dimensional representations of the degenerate (or graded) affine Hecke algebra H of GL. These functors…

q-alg · Mathematics 2007-05-23 T. Arakawa , T. Suzuki

Given a simple vertex algebra A and a reductive group G of automorphisms of A, the invariant subalgebra A^G is strongly finitely generated in most examples where its structure is known. This phenomenon is subtle, and is generally not true…

Representation Theory · Mathematics 2020-08-10 Andrew R. Linshaw