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Related papers: A note on graded hypersurface singularities

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In this paper, I present some sufficient conditions for projective hypersurfaces to be GIT (semi-)stable. These conditions will be presented in terms of dimension and degree of the hypersurfaces, dimension of the singular locus and…

Algebraic Geometry · Mathematics 2025-10-07 Xuancong He

We study normal forms of germs of singular real-analytic Levi-flat hypersurfaces. We prove the existence of rigid normal forms for singular Levi-flat hypersurfaces which are defined by the vanishing of the real part of complex…

Complex Variables · Mathematics 2018-10-16 Arturo Fernández-Pérez , Gustavo Marra

We find the first examples of real hypersurfaces with two nonconstant principal curvatures in complex projective and hyperbolic planes, and we classify them. It turns out that each such hypersurface is foliated by equidistant Lagrangian…

Differential Geometry · Mathematics 2013-10-02 J. Carlos Diaz-Ramos , Miguel Dominguez-Vazquez , Cristina Vidal-Castiñeira

In this article we study the cohomological and homological (due to Jannsen) Hodge conjecture for singular varieties. The motivation for studying singular varieties comes from the fact that any smooth projective variety X is birational to a…

Algebraic Geometry · Mathematics 2025-10-01 Ananyo Dan , Inder Kaur

Recent work ([18], [1]) has produced a complete list of weighted homogeneous surface singularities admitting smoothings whose Milnor fibre has only trivial rational homology (a "rational homology disk"). Though these special singularities…

Algebraic Geometry · Mathematics 2013-10-25 Jonathan Wahl

We characterize quasihomogeneity of isolated singularities by the injectivity of the map induced by the first differential of the logarithmic differential complex in the top local cohomology supported in the singular point.

Algebraic Geometry · Mathematics 2008-06-19 Michel Granger , Mathias Schulze

We prove that certain asymptotically flat initial data sets with nontrivial topology and/or differentiable structure collapse to form singularities. The class of such initial data sets is characterized by a new smooth invariant, the maximal…

General Relativity and Quantum Cosmology · Physics 2010-06-16 Kristin Schleich , Donald M. Witt

We study F-blowups of non-F-regular normal surface singularities. Especially the cases of rational double points and simple elliptic singularities are treated in detail.

Algebraic Geometry · Mathematics 2024-02-27 Nobuo Hara , Tadakazu Sawada , Takehiko Yasuda

We use classical invariant theory to construct invariants of complex graded Gorenstein algebras of finite vector space dimension. As a consequence, we obtain a way of extracting certain numerical invariants of quasi-homogeneous isolated…

Complex Variables · Mathematics 2012-07-03 M. G. Eastwood , A. V. Isaev

I describe the monodromy of smooth hypersurfaces $X$ of high degree in a fixed smooth variety $Y$ containing a fixed subvariety $W$ of $Y$. The cohomology of $X$ in middle degree spanned by the pull-back of the cohomology of $Y$ and by the…

Algebraic Geometry · Mathematics 2007-05-23 Ania Otwinowska

The two-fold singularity has played a significant role in our understanding of uniqueness and stability in piecewise smooth dynamical systems. When a vector field is discontinuous at some hypersurface, it can become tangent to that surface…

Dynamical Systems · Mathematics 2015-06-03 Mike R. Jeffrey

We study singular hypersurfaces in tensor multi-scalar theories of gravity. We derive in a distributional and then in an intrinsic way, the general equations of junction valid for all types of hypersurfaces, in particular for lightlike…

General Relativity and Quantum Cosmology · Physics 2011-05-12 C. Barrabes , G. F. Bressange

We associate (under a minor assumption) to any analytic isolated singularity of dimension $n\geq 2$ the `analytic lattice cohomology' ${\mathbb H}^*_{an}=\oplus_{q\geq 0}{\mathbb H}^q_{an}$. Each ${\mathbb H}^q_{an}$ is a graded ${\mathbb…

Algebraic Geometry · Mathematics 2021-09-24 Tamás Ágoston , András Némethi

We present a classification algorithm for isolated hypersurface singularities of corank 2 and modality 1 over the real numbers. For a singularity given by a polynomial over the rationals, the algorithm determines its right equivalence class…

Algebraic Geometry · Mathematics 2020-10-16 Janko Boehm , Magdaleen S. Marais , Andreas Steenpass

The focus of this article is the study of a certain type of singularities and their transfer properties in a universally equidimensional morphism (i.e. an open morphism with constant pure-dimensional fibers). The singularities of interest…

Algebraic Geometry · Mathematics 2025-07-08 Mohamed Kaddar

A new construction is presented of scalar-flat Kaehler metrics on non-minimal ruled surfaces. The method is based on the resolution of singularities of orbifold ruled surfaces which are closely related to rank-2 parabolically stable…

Differential Geometry · Mathematics 2007-05-23 Yann Rollin , Michael A. Singer

In the author's earlier work there appeared a new way to specify any smooth closed 4-manifold by a surface diagram, which consists of an orientable surface decorated with simple closed curves. These curves are cyclically indexed, and each…

Geometric Topology · Mathematics 2018-04-26 Jonathan D. Williams

Given a hypersurface $M$ of null scalar curvature in the unit sphere $\mathbb{S}^n$, $n\ge 4$, such that its second fundamental form has rank greater than 2, we construct a singular scalar-flat hypersurface in $\Rr^{n+1}$ as a normal graph…

Differential Geometry · Mathematics 2008-12-16 Jorge H. S. de Lira , Marc Soret

We study the uniqueness of horospheres and equidistant spheres in hyperbolic space under different conditions. First we generalize the Bernstein theorem by Do Carmo and Lawson to the embedded hypersurfaces with constant higher order mean…

Differential Geometry · Mathematics 2024-12-24 Barbara Nelli , Jingyong Zhu

For a subvariety of a smooth projective variety, consider the family of smooth hypersurfaces of sufficiently large degree containing it, and take the quotient of the middle cohomology of the hypersurfaces by the cohomology of the ambient…

Algebraic Geometry · Mathematics 2007-05-23 Ania Otwinowska , Morihiko Saito