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We present two results about the relationship between fundamental groups of quasiprojective manifolds and linear systems on a projectivization. We prove the existence of a plane curve with non-abelian fundamental group of the complement…

Algebraic Geometry · Mathematics 2018-05-04 Enrique Artal Bartolo , José Ignacio Cogolludo-Agustín

We investigate new Clairaut conditions for anti-invariant submersions from normal almost contact metric manifolds onto Riemannian manifolds. We prove that there is no Clairaut anti-invariant submersion admitting vertical Reeb vector field…

Differential Geometry · Mathematics 2017-04-03 Hakan Mete Taştan , Sibel Gerdan

We show that an enlargeable Riemannian metric on a (possibly nonspin) manifold cannot have uniformly positive scalar curvature. This extends a well-known result of Gromov and Lawson to the nonspin setting. We also prove that every…

Geometric Topology · Mathematics 2021-01-01 Simone Cecchini , Thomas Schick

This paper compares two invariants of foliated manifolds which seem to measure the non-Hausdorffness of the leaf space: the transversal length on the fundamental group and the foliated Gromov norm on the homology. We consider foliations…

Algebraic Topology · Mathematics 2015-12-08 Thilo Kuessner

We prove complete reducibility for an integrable module for an affine Lie algebra where the canonical central element acts non-trivially. We further prove that integrable modules does not exists for most of the super affine Lie algebras…

Representation Theory · Mathematics 2007-05-23 S. Eswara Rao

In this paper, we study the property of weak approximation with Brauer-Manin obstruction for surfaces with respect to field extensions of number fields. For any nontrivial extension of number fields L/K, assuming a conjecture of M. Stoll,…

Number Theory · Mathematics 2022-09-05 Han Wu

We consider finite extensions of the rationals which are unramified except for at 2 and infinity. We show there are no such extensions of degrees 9 through 15.

Number Theory · Mathematics 2007-10-16 John W. Jones

We show there are no extremal metrics for the eigenvalues of the Neumann Laplacian on any compact manifold. Nonetheless, we construct examples of conformally extremal metrics for the eigenvalues of this operator in any annulus and…

Differential Geometry · Mathematics 2024-05-07 Eduardo Longa

We show that conformal geodesics on a Riemannian manifold cannot spiral: there does not exist a conformal geodesic which becomes trapped in every neighbourhood of a point.

Differential Geometry · Mathematics 2025-07-25 Peter Cameron , Maciej Dunajski , Paul Tod

In this paper, we study extensions of valuations over algebraic field extensions without the use of the Axiom of Choice. We show a bijection between the extensions of a valuation and the maximal ideals of the relative integral closure of…

Commutative Algebra · Mathematics 2025-11-11 Cédric Aïd

Relying on a recent criterion, due to A.~Petrunin [18], to check if a complete, non-compact, Riemannian manifold admits an isometric embedding into a Euclidean space with positive reach, we extend to manifolds with such property the…

Analysis of PDEs · Mathematics 2025-01-28 Federico Luigi Dipasquale

We prove that there are only finitely many isoparametrically foliated closed connected Riemannian manifolds with bounded geometry, fixed dimension $n\neq5$, and finite fundamental group, up to foliated diffeomorphism. In addition, we…

Differential Geometry · Mathematics 2026-03-24 Manuel Krannich , Alexander Lytchak , Marco Radeschi

In this note we show that the integral means spectrum of any univalent function admitting a quasiconformal extension to the extended complex plane is strictly less than the universal integral means spectrum. This gives an affirmative answer…

Complex Variables · Mathematics 2024-08-23 Jianjun Jin

In this article, we prove an extension property of semipositively metrized ample invertible sheaves on a projective scheme over a complete non-archimedean valued field. As an application, we establish a Nakai-Moishezon type criterion for…

Algebraic Geometry · Mathematics 2015-11-24 Huayi Chen , Atsushi Moriwaki

The strong no loop conjecture states that a simple module of finite projective dimension over an artin algebra has no non-zero self-extension. The main result of this paper establishes this well known conjecture for finite dimensional…

Representation Theory · Mathematics 2012-09-13 Kiyoshi Igusa , Shiping Liu , Charles Paquette

After surveying existing proofs that every closed, orientable 3-manifold is parallelizable, we give three proofs using minimal background. In particular, our proofs use neither spin structures nor the theory of Stiefel-Whitney classes.

Geometric Topology · Mathematics 2018-08-07 Riccardo Benedetti , Paolo Lisca

We investigate necessary and sufficient conditions for the extendibility and boundedness of Gaussian curvature, Mean curvature and principal curvatures near all types of singularities on fronts. We also study the convergence to infinite…

Differential Geometry · Mathematics 2021-07-16 Tito Alexandro Medina Tejeda

We prove that the finitistic dimension conjecture, the Gorenstein Symmetry Conjecture, the Wakamatsu-tilting conjecture and the generalized Nakayama conjecture hold for artin algebras which can be realized as endomorphism algebras of…

Representation Theory · Mathematics 2008-04-14 Jiaqun Wei

We introduce the notion of "functional extension" of a set X, by means of two natural algebraic properties of the operator * on unary functions. We study the connections with ultrapowers of structures with universe X, and we give a simple…

Logic · Mathematics 2017-12-19 Marco Forti

In this paper we introduce the notion of pure non-characteristically nilpotent Lie algebra and under a condition we prove that a complex maximal extension of a finite-dimensional pure non-characteristically nilpotent Lie algebra is…

Rings and Algebras · Mathematics 2022-07-21 K. K. Abdurasulov , B. A. Omirov
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