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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.

169,341 papers · 148 categories

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7142027 · Oct 202519922001200920182026
48 results for homotopy inequivalent

For each pair of integers g at least 2 and h at least 1, we explicitly construct infinitely many fiber sum and section sum indecomposable genus g surface bundles over genus h surfaces whose total spaces are pairwise homotopy inequivalent.

2012-09-06abs ↗pdf ↗

We discuss the Sasakian geometry of odd dimensional homotopy spheres. In particular, we give a completely new proof of the existence of metrics of positive Ricci curvature on exotic spheres that can be realized as the boundary of a parallelizable manifold. Furthermore, it is shown that on such homotopy spheres $\script…

2002-01-16abs ↗pdf ↗

We define an simple invariant of an embedded nullhomologous Lagrangian torus and use this invariant to show that many symplectic 4-manifolds have infinitely many pairwise symplectically inequivalent nullhomologous Lagrangian tori. We further show that for a large class of examples that lambda(T) is actually a C-infinit…

2003-04-25abs ↗pdf ↗

New examples of knots with infinitely many inequivalent slice disks.

problem Existence of knots with infinitely many pairwise nonisotopic slice disks.
method Classification of fibered, homotopy-ribbon disks and use of satellite operations.
result Examples of fibered, hyperbolic knots bounding infinitely many fibered, ribbon disks that are pairwise nonisotopic modulo local knotting.

In this note we prove that, for any integer n, there exist a smooth 4-manifold, homotopic to a K3 surface, defined by applying the link surgery method of Fintushel-Stern to a certain 2-component graph link, which admits n inequivalent symplectic structures Keywords: Symplectic topology of 4-manifolds; Seiberg-Witten th…

2001-03-25abs ↗pdf ↗

New knots have same group, quandle, but different homotopy invariants.

problem Determining knot homotopy type from group, quandle, and module.
method Construction of 2-knots with isomorphic knot groups and fundamental quandles but distinct first Postnikov invariants.
result Fundamental quandle does not determine the first Postnikov invariant of 2-knots.

The paper defines and classifies Cappell-Shaneson polynomials.

problem Characterizing Cappell-Shaneson polynomials.
method Algebraic conditions on polynomials, reduction modulo primes, and construction of infinite series.
result Complete lists of Cappell-Shaneson polynomials of degrees 4 and 5, and several infinite series of degree 6.

Using S1S^1-equivariant symplectic homology, in particular its mean Euler characteristic, of the natural filling of links of Brieskorn-Pham polynomials, we prove the existence of infinitely many inequivalent contact structures on various manifolds, including in dimension 5 the k-fold connected sums of S2×S3S^2\times S^3 a…

2015-06-29abs ↗pdf ↗

The study classifies nilpotent Lie algebras up to dimension 9.

problem Classifying nilpotent Lie algebras up to equivalence.
method Developed an algorithm to classify nilpotent Lie algebras of dimension up to 9, and determined the number of inequivalent nice bases for dimensions up to 7.
result Any nilpotent Lie algebra of dimension n has at most countably many inequivalent nice bases.

We have a knot quandle and a fundamental class as invariants for a surface-knot. These invariants can be defined for a classical knot in a similar way, and it is known that the pair of them is a complete invariant for classical knots. In this paper, we compare a situation in surface-knot theory with that in classical k…

2005-12-05abs ↗pdf ↗

New examples of knotting phenomena in 4-manifolds with specific fundamental groups.

problem Finding 2-spheres in simply connected 4-manifolds with prescribed fundamental groups.
method Construction of infinite sets of pairwise smoothly inequivalent 2-spheres that are topologically isotopic.
result First known examples of knotting phenomena in 4-manifolds with specific properties.

Proves existence of many non-R\mathbb R-covered Anosov flows on hyperbolic 3-manifolds.

problem Existence of many non-R\mathbb R-covered Anosov flows on hyperbolic 3-manifolds.
method Description of clusters of lozenges in orbit spaces of constructed Anosov flows.
result Existence of hyperbolic 3-manifolds carrying many pairwise orbitally inequivalent quasi-geodesic Anosov flows.

Study symplectic structures on open 4-manifolds with distinct primitive cohomologies.

problem Identifying symplectic structures with non-isomorphic primitive cohomology.
method Analyze fibrations and compute monodromy explicitly for specific link complements.
result Symplectic structures on open 4-manifolds can have different primitive cohomology dimensions.

This paper investigates which smooth manifolds arise as quotients (orbit spaces) of flows of vector fields. Such quotient maps were already known to be surjective on fundamental groups, but this paper shows that every epimorphism of countably presented groups is induced by the quotient map of some flow, and that higher…

2014-12-31abs ↗pdf ↗

We consider contact structures on simply-connected 5-manifolds which arise as circle bundles over simply-connected symplectic 4-manifolds and show that invariants from contact homology are related to the divisibility of the canonical class of the symplectic structure. As an application we find new examples of inequival…

2010-01-12abs ↗pdf ↗

In this article we study Lefschetz fibration structures on knot surgery 4-manifolds obtained from an elliptic surface E(2) using Kanenobu knots KK. As a result, we get an infinite family of simply connected mutually diffeomorphic 4-manifolds coming from a pair of inequivalent Kanenobu knots. We also obtain an infinite…

2009-06-28abs ↗pdf ↗

The paper studies embeddings of surfaces in 3-sphere, defining new invariants to distinguish knots and surfaces.

problem Embeddings of oriented surfaces in the 3-sphere and distinguishing them.
method Defining the fundamental span as a complete invariant, deriving computable invariants from it.
result New invariants distinguish inequivalent handlebody knots and bi-knotted surfaces.

It is well known that every compact simple Lie group G admits an Einstein metric that is invariant under the independent left and right actions of G. In addition to this bi-invariant metric, with G x G symmetry, it was shown by D'Atri and Ziller that every compact simple Lie group except SU(2) and SO(3) admits at least…

2010-01-18abs ↗pdf ↗

A surface automorphism is strongly irreducible if every essential simple closed curve in the surface has nontrivial geometric intersection with its image. We show that a three-manifold admits only finitely many inequivalent surface bundle structures with strongly irreducible monodromy.

2002-08-14abs ↗pdf ↗

The study finds infinitely many Lefschetz pencils on ruled surfaces with negative Euler characteristic.

problem Finding Lefschetz pencils on ruled surfaces with negative Euler characteristic.
method Building Lefschetz fibrations on a blow-up of the surface via partial conjugation, then showing compatibility with a symplectic form.
result Ruled surfaces with negative Euler characteristic admit infinitely many inequivalent Lefschetz pencils and fibrations.

We show that #8(S^2 times S^3) admits two 8-dimensional complex families of inequivalent non-regular Sasakian-Einstein structures. These are the first known non-regular Sasakian-Einstein metrics on this 5-manifold.

2002-08-26abs ↗pdf ↗

Three disjoint rays in euclidean 3-space form Borromean rays provided their union is knotted, but the union of any two components is unknotted. We construct infinitely many Borromean rays, uncountably many of which are pairwise inequivalent. We obtain uncountably many Borromean hyperplanes.

2012-11-27abs ↗pdf ↗

It is well known that every compact simple group manifold G admits a bi-invariant Einstein metric, invariant under G_L\times G_R. Less well known is that every compact simple group manifold except SO(3) and SU(2) admits at least one more homogeneous Einstein metric, invariant still under G_L but with some, or all, of t…

2009-03-16abs ↗pdf ↗

In this note we present a new definition of the 4-manifold admitting inequivalent symplectic structures constructed by McMullen-Taubes which leads to the identification of a new symplectic structure. We prove moreover that it is diffeomorphic to one of the link surgery manifolds introduced by Fintushel-Stern.

2001-03-30abs ↗pdf ↗

The paper realizes Lie superalgebras G(3) and F(4) as symmetries of supergeometries.

problem Addressing whether exceptional Lie superalgebras G(3) and F(4) are maximal symmetries of supergeometries.
method Considering negatively graded Lie superalgebras for every choice of parabolic subgroup, computing Tanaka-Weisfeiler prolongations, and reducing the structure group when required.
result Realization of 19 inequivalent G(3)-supergeometries and 55 inequivalent F(4)-supergeometries.

We classify all the non-hyperbolic Dehn fillings of the complement of the chain-link with 3 components, conjectured to be the smallest hyperbolic 3-manifold with 3 cusps. We deduce the classification of all non-hyperbolic Dehn fillings of infinitely many 1-cusped and 2-cusped hyperbolic manifolds, including most of tho…

2002-04-18abs ↗pdf ↗

In this paper, we demonstrate that the complete hyperbolic structure of various two-bridge knots and links cannot be deformed to an inequivalent strictly convex projective structure. We also prove a complementary result showing that under certain rigidity hypotheses, branched covers of amphicheiral knots admit non-triv…

2012-10-31abs ↗pdf ↗

We exhibit large classes of local actions for the vacuum Einstein equations. In presence of fermions, or more generally of matter which couple to the connection, these actions lead to inequivalent equations revealing an arbitrary number of parameters. Even in the pure gravitational sector, any corresponding quantum the…

2009-07-17abs ↗pdf ↗

Veech groups uniformize Teichmüller geodesic curves in Riemann moduli space. Recently, examples of infinitely generated Veech groups have been given. We show that these can even have infinitely many cusps and infinitely many infinite ends. We further show that examples exist for which each direction of an infinite end …

2004-10-06abs ↗pdf ↗

Following an example discovered by John Berge, we show that there is a 4-component link L \subset (S^1 x S^2)#(S^1 x S^2) so that, generically, the result of Dehn surgery on L is a 3-manifold with two inequivalent genus 2 Heegaard splittings, and each of these Heegaard splittings is of Hempel distance 3.

2010-02-25abs ↗pdf ↗