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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.

168,657 papers · 148 categories

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1122 · Jun 201319922001200920172026
48 results for Akbulut

The paper proves trisection genus of Akbulut cork and constructs many corks with trisection genus 3.

problem Determining the trisection genus of contractible 4-manifolds and exotic pairs.
method Proved trisection genus of Akbulut cork and constructed corks with trisection genus 3.
result First examples of contractible 4-manifolds with determined trisection genus except for 4-ball.

We first construct a genus zero positive allowable Lefschetz fibration over the disk (a genus zero PALF for short) on the Akbulut cork and describe the monodromy as a positive factorization in the mapping class group of a surface of genus zero with five boundary components. We then construct genus zero PALFs on infinit…

2014-06-23abs ↗pdf ↗

We construct a genus zero PALF structure on each of plugs introduced by Akbulut and Yasui and describe the monodromy as a positive factorization in the mapping class group of a fiber. We also examine the monodromies of PALFs on a certain pair of compact Stein surfaces such that one is obtained by applying a plug twist …

2019-06-10abs ↗pdf ↗

Akbulut has recently shown that an infinite family of Cappell-Shaneson homotopy 4-spheres is diffeomorphic to the standard 4-sphere. In the present paper, a strictly larger family is shown to be standard by a simpler method. This new approach uses no Kirby calculus except through the relatively simple 1979 paper of Akb…

2009-08-13abs ↗pdf ↗

Any bounding compact smooth manifold bounds a compact manifold with a spine consisting of transversely intersecting codimension one submanifolds. This paper provides details for a picture proof given in previous papers with S. Akbulut.

2016-02-08abs ↗pdf ↗

We call an integral homology sphere non-trivially\textit{non-trivially} bounds a rational homology ball if it is obstructed from bounding an integral homology ball. After Fintushel and Stern's well-known example Σ(2,3,7)Σ(2,3,7), Akbulut and Larson recently provided the first infinite families of Brieskorn spheres non-trivially boundin…

2019-12-10abs ↗pdf ↗

We utilize the Ozsvath-Szabo contact invariant to detect the action of involutions on certain homology spheres that are surgeries on symmetric links, generalizing a previous result of Akbulut and Durusoy. Potentially this may be useful to detect different smooth structures on 4-manifolds by cork twisting operation.

2011-04-12abs ↗pdf ↗

Operators on the ring of algebraically constructible functions are used to compute local obstructions for a four-dimensional semialgebraic set to be homeomorphic to a real algebraic set. The link operator and arithmetic operators yield 243432^{43}-43 independent characteristic numbers mod 2, which generalize the Akbulut-K…

1998-09-11abs ↗pdf ↗

Recently Auckly-Kim-Melvin-Ruberman showed that for any finite subgroup G of SO(4) there exists a contractible 4-manifold with an effective G-action on its boundary so that the twists associated to the non-trivial elements of G do not extend to diffeomorphisms of the entire manifold. We use a Heegaard Floer theoretic a…

2016-09-15abs ↗pdf ↗

We consider a family of corks, denoted WnW_n, constructed by Akbulut and Yasui. Each cork gives rise to an exotic structure on a smooth 4-manifold via a twist ττ on its boundary Σn=WnΣ_n = \partial W_n. We compute the instanton Floer homology of ΣnΣ_n and show that the map induced on the instanton Floer homology by $τ: Σ…

2013-04-18abs ↗pdf ↗

In this paper we find infinitely many Mazur type manifolds and corks with shadow complexity one among the 4-manifolds constructed from contractible special polyhedra having one true vertex by using the notion of Turaev's shadow. We also find such manifolds among 4-manifolds constructed from Bing's house. Our manifolds …

2015-05-04abs ↗pdf ↗

Fintushel-Stern's knot surgery gave many pairs of exotic manifolds, which are homeomorphic but non-diffeomorphic. We show that if an elliptic fibration has two parallel, oppositely oriented vanishing circles (for example S2×S2S^2\times S^2 or Matsumoto's S4S^4), then the knot surgery gives rise to standard manifolds. The …

2010-11-24abs ↗pdf ↗

We show that, for each integer n, there exist infinitely many pairs of n-framed knots representing homeomorphic but non-diffeomorphic (Stein) 4-manifolds, which are the simplest possible exotic 4-manifolds regarding handlebody structures. To produce these examples, we introduce a new description of cork twists and util…

2015-05-11abs ↗pdf ↗

The algorithm given by Akbulut-Ozbagci constructs an explicit open book decomposition on a contact three-manifold described by a contact surgery on a link in the three-sphere. In this article, we will improve this algorithm by using Giroux's contact cell decomposition process. Our algorithm is more economical on choosi…

2007-04-12abs ↗pdf ↗

In this paper, we investigate existence of inequivalent smooth structures on closed smooth non-orientable 4-manifolds building upon results of Akbulut, Cappell-Shaneson, Fintushel-Stern, Gompf, and Stolz. We add to the number of known constructions and provide new examples of exotic manifolds that are obtained as an ap…

2013-06-11abs ↗pdf ↗

Fast and efficient homology algorithms are in demand in the applied sciences for analyzing solid materials and proteins, processing digital imaging data, or pattern classification among others. Recent advances employ discrete Morse theory as a preprocessor. Research in this area has lead to the need to find complicated…

2013-02-27abs ↗pdf ↗

All link types arise from semiholomorphic polynomials.

problem Proving every link type can be represented by semiholomorphic polynomials.
method Constructive proof showing every link type arises from a weakly isolated singularity of a semiholomorphic polynomial.
result Every link type in the 3-sphere arises as the link of a weakly isolated singularity of a semiholomorphic polynomial.

Using the Cartan-Kahler theory, and results on real algebraic structures, we prove two embedding theorems. First, the interior of a smooth, compact 3-manifold may be isometrically embedded into a G_2-manifold as an associative submanifold. Second, the interior of a smooth, compact 4-manifold K, whose double has a trivi…

2007-08-09abs ↗pdf ↗

One can define what it means for a compact manifold with corners to be a "contractible manifold with contractible faces." Two combinatorially equivalent, contractible manifolds with contractible faces are diffeomorphic if and only if their 4-dimensional faces are diffeomorphic. It follows that two simple convex polytop…

2013-06-25abs ↗pdf ↗

3-dimensional Harvey Lawson submanifolds were introduced in an earlier paper by Akbulut-Salur, as examples of Lagrangian-type manifolds inside G2 manifold. In this paper, we first show that the space of deformations of a smooth, compact, orientable Harvey-Lawson submanifold HL in a G2 manifold M can be identified with …

2015-03-10abs ↗pdf ↗

Article generalizes open book construction for 5D contact pairs.

problem Constructing compatible open books on relative contact pairs.
method Introduces generalized square bridge position for 5D Legendrian links.
result Algorithm constructs relative open book decompositions on relative contact pairs.

Here we prove that up to diffeomorphism every compact Stein manifold W of dimension 2n+2>4 admits a Lefschetz fibration over the two-disk with Stein regular fibers, such that the monodromy of the fibration is a symplectomorphism induced by compositions of right-handed Dehn twists along embedded Lagrangian n-spheres on …

2010-03-10abs ↗pdf ↗

The author recently proved the existence of an infinite order cork: a compact, contractible submanifold CC of a 4-manifold and an infinite order diffeomorphism ff of C\partial C such that cutting out CC and regluing it by distinct powers of ff yields pairwise nondiffeomorphic manifolds. The present paper exhibits …

2016-07-15abs ↗pdf ↗

Study shows challenges in reinforcement learning math problems, proposing enhancements and a hardness measure.

problem Challenges in reinforcement learning finding rare high-reward instances.
method Combining combinatorial group theory, algorithmic enhancements, and topological hardness measure.
result Resolved mathematical questions and proposed enhancements for reinforcement learning.

A simple characterization is given of open subsets of a complex surface that smoothly perturb to Stein open subsets. As applications, complex 2-space C^2 contains domains of holomorphy (Stein open subsets) that are exotic R^4's, and others homotopy equivalent to the 2-sphere but cut out by smooth, compact 3-manifolds. …

2011-10-09abs ↗pdf ↗

It is known that there is a unique concordance class in the free homotopy class of S1×ptS1×S2S^1\times pt \subset S^1 \times S^2. The constructive proof of this fact is given by the second author. It turns out that all the concordances in this construction are invertible. The knots KS1×S2K\subset S^{1}\times S^{2} with hyperbolic …

2019-01-03abs ↗pdf ↗

The paper constructs new rational homology 3-spheres bounding rational homology 4-balls.

problem Constructing rational homology 3-spheres that bound rational homology 4-balls.
method Exploring plumbed 3-manifolds and using rational homology circles.
result Infinite families of rational homology 3-spheres that bound rational homology 4-balls.

By using the relation between foliations and exotic R^4, orbifold KK-theory deformed by a gerbe can be interpreted as coming from the change in the smoothness of R^4. We give various interpretations of integral 3-rd cohomology classes on S^3 and discuss the difference between large and small exotic R^4. Then we show t…

2009-11-02abs ↗pdf ↗