Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,291 papers · 148 categories

Trend · papers per month

25.0%50.0%75.0%100.0% · Sep 199219922001200920182026
48 results for positive second intersection form

Study on 4-manifolds with exotic smooth structures and Z_2 fundamental group.

problem Exploring smooth structures on 4-manifolds with specific fundamental groups.
method Construction of irreducible, smooth, oriented, closed, definite 4-manifolds with Z_2 fundamental group and specific Betti numbers.
result Proves existence of infinitely many smooth structures on definite 4-manifolds with positive second Betti number and Z_2 fundamental group.

The paper calculates 4-manifold properties from a trisection diagram.

problem Computing the homology and intersection form of a 4-manifold from a trisection diagram.
method Expressing the homology and intersection form in terms of curves and intersection pairing on the diagram surface.
result Explicit formulas for the second and third homology groups of XX and an algorithm to compute the intersection form.

Let X be a pseudomanifold. In this text, we use a simplicial blow-up to define a cochain complex whose cohomology with coefficients in a field, is isomorphic to the intersection cohomology of X, introduced by M. Goresky and R. MacPherson. We do it simplicially in the setting of a filtered version of face sets, also cal…

2012-05-31abs ↗pdf ↗

Paper calculates homology and intersection form of trisected 4-manifolds with boundary.

problem Calculating homology and intersection form of trisected 4-manifolds with boundary.
method Uses relative trisection diagrams to calculate homology and intersection form.
result Describes a representative of the second Stiefel-Whitney class using relative trisection diagrams.

Proves intersection properties of minimal hypersurfaces in various spaces.

problem Intersection properties of minimal hypersurfaces in different geometric settings.
method Two approaches: classifications of stable minimal hypersurfaces and conformal change with comparison geometry.
result Intersection properties for minimal hypersurfaces in specific geometric settings, including free boundary minimal hypersurfaces.

The first part of this paper exposits a simple geometric description of the Kirby-Siebenmann invariant of a 4--manifold in terms of a quadratic refinement of its intersection form. This is the first in a sequence of higher-order intersection invariants of Whitney towers studied by the authors, particularly for the 4--b…

2012-06-30abs ↗pdf ↗

Sharp curvature condition implies spherical space form structure.

problem Characterizing manifolds with specific curvature properties.
method Proving diffeomorphism and homeomorphism to spherical space forms using curvature conditions.
result Closed manifolds with $4 rac{1}{2}$-positive curvature operator of the second kind are spherical space forms.

Study shows finiteness of certain definite 4-manifolds bounded by rational homology 3-spheres.

problem Understanding the intersection forms of definite 4-manifolds bounded by rational homology 3-spheres.
method Utilized constraints from Donaldson's diagonalization theorem, Frøyshov's correction term invariants, and Ozsváth and Szabó's invariants.
result There are finitely many negative definite lattices up to stable-equivalence that can be realized as intersection forms of 4-manifolds bounded by a rational homology 3-sphere.

Positivity of intersections in 4-manifolds leads to taming symplectic structures.

problem Taming symplectic structures in almost complex 4-manifolds.
method Proof of positivity of intersections of pseudoholomorphic curves.
result Positivity of intersections is stable and leads to taming symplectic structures.

Study the intersection of positive closed currents using tangent currents and King's residue formula.

problem Investigate the intersection of positive closed currents in complex manifolds.
method Employ tangent currents and King's residue formula to establish a natural condition for intersection.
result Derive an integral representation of the intersection of positive closed currents.

Let Aut(H1(Ng;Z2),)\operatorname{Aut}(H_1(N_g;\mathbb Z_2),\cdot ) be the group of automorphisms on the first homology group with Z2\mathbb Z_2 coefficient of a closed non-orientable surface NgN_g preserving the mod 22 intersection form. In this paper, we obtain a finite presentation for $\operatorname{Aut}(H_1(N_g;\mathbb Z_2),\c…

2014-10-27abs ↗pdf ↗

Paper characterizes CP² using Ricci flow and conformal invariants.

problem Characterize CP² using geometric invariants and Ricci flow.
method Introduce conformal invariant β, use Ricci flow to relate β bounds to curvature.
result Proves CP² is the only 4-manifold with positive second positive intersection form and specific β bound.

This paper considers aspects of 4-manifold topology from the point of view of the null cone of a neutral metric, a point of view we call neutral causal topology. In particular, we construct and investigate neutral 4-manifolds with null boundaries that arise from canonical 3- and 4-dimensional settings. A null hypersurf…

2016-05-31abs ↗pdf ↗

Study on second homology group of genus 3 hyperelliptic Torelli group.

problem Understanding the structure of second homology group of genus 3 hyperelliptic Torelli group.
method Analyzing abelian cycles associated with disjoint separating curves and their algebraic properties.
result Simple abelian cycles are linearly independent in the second homology group.

The paper shows that certain 4D manifolds with specific harmonic forms are diffeomorphic to CP2.

problem Characterizing 4D Riemannian manifolds with harmonic 2-forms of constant length.
method Analyzing properties of manifolds with positive sectional curvature and harmonic 2-forms.
result Compact 4D manifolds with harmonic 2-forms of constant length are diffeomorphic to CP2 under certain conditions.

Proves Riemannian positive mass theorem with singularities.

problem Proves Riemannian positive mass theorem for specific types of singular manifolds.
method Uses initial data sets with a second fundamental form to transfer convexity between different singularity components.
result Proves the theorem for manifolds with some mean-concave components and others mean-convex.

A topologically minimal surface may be isotoped into a normal form with respect to a fixed triangulation. If the intersection with each tetrahedron is simply connected, then the pieces of this normal form are triangles, quadrilaterals, and helicoids. Helical pieces can have any number of positive or negative twists. We…

2015-02-19abs ↗pdf ↗

Study curvature operator on Riemannian manifolds, proving new classification results.

problem Classifying Riemannian manifolds based on the curvature operator of the second kind.
method Analyzing the curvature operator and proving classification theorems.
result Closed manifolds with specific curvature properties are classified.

Classifies definite forms from surgeries on knots with small slice genus.

problem Classifying definite forms from surgeries on knots with specific properties.
method Uses Yang--Mills instanton gauge theory and Heegaard Floer correction terms.
result Classifies positive definite intersection forms for surgeries on knots with slice genus at most 2.

We define non-pluripolar products of closed positive currents on a compact Kaehler manifold. We show that a positive non-pluripolar measure can be written in a unique way as the top degree self-intersection (in the non-pluripolar sense) of a closed positive current in given big cohomology class. The solution is shown t…

2008-12-18abs ↗pdf ↗

An oriented compact 4-manifold VV with boundary S3S^3 is called a positon (resp. negaton) if its intersection form is positive definite (resp. negative definite) and it is simply connected. In this paper, we prove that there exist infinitely many knots which cannot bound null-homologous disks either in positons or in …

2015-12-30abs ↗pdf ↗

The paper resolves a conjecture about curvature conditions on manifolds.

problem Investigating curvature conditions on manifolds to settle a conjecture.
method Analyzing curvature of the second kind and using Brendle's PIC1 condition.
result Manifolds with positive curvature of the second kind are diffeomorphic to a sphere.

A method to compute intersection numbers with matrices of positive corank.

problem Computing the intersection number of maps with matrices of positive corank.
method Extending intersection number definition to stratified sets, using homotopy invariants and Stiefel manifolds.
result An effective method to compute the intersection number in polynomial cases.

The paper introduces generalized Lelong numbers for currents and their applications in intersection theory.

problem Defining and studying generalized Lelong numbers for currents in intersection theory.
method Formulating generalized Lelong numbers for closed smooth (j,j)-forms, defining horizontal dimension, and establishing properties and formulas.
result Effective sufficient conditions for defining and continuity of intersections of positive closed currents.

We prove that any compact selfdual Einstein 4-orbifold of positive scalar curvature whose isometry group contains a 2-torus is, up to an orbifold covering, a quaternion Kaehler quotient of (k-1)-dimensional quaternionic projective space by a (k-2)-torus for some k2k\geq 2. We also obtain a topological classification in…

2004-05-02abs ↗pdf ↗

Paper proves positivity of Chern-Weil forms for certain vector bundles.

problem Proving positivity of Chern-Weil forms for Griffiths semipositive vector bundles.
method Analyzing characteristic differential forms and Schur polynomials.
result Positivity of c1(E,h)c2(E,h)c3(E,h)c_1(E,h) \wedge c_2(E,h) - c_3(E,h) established.

The first part of this paper completes the classification of Whitney towers in the 4-ball that was started in three related papers. We provide an algebraic framework allowing the computations of the graded groups associated to geometric filtrations of classical link concordance by order n (twisted) Whitney towers in th…

2011-01-18abs ↗pdf ↗

The paper proves a category of dg manifolds with finite positive amplitude.

problem Understanding the structure of dg manifolds with finite positive amplitude.
method Using path spaces and homotopy transfer theorem for curved L[1]L_\infty[1]-algebras.
result Proves that dg manifolds of finite positive amplitude form a category of fibrant objects.