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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.

168,695 papers · 148 categories

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57114170227 · Jun 202619922001200920172026
48 results for non-orientable manifolds

Study trisections of non-orientable 4-manifolds with boundary.

problem Understanding trisections in non-orientable 4-manifolds.
method Introduced trisections of non-orientable 4-manifolds with boundary, proved a non-orientable analogue of a theorem, and discussed adaptation of trisection theory.
result Existence of trisection diagrams and Kirby diagrams for closed non-orientable 4-manifolds.

Minimal stretch factor for non-orientable surfaces is small.

problem Finding the minimal stretch factor for pseudo-Anosov homeomorphisms on non-orientable surfaces.
method Adapting Thurston's theory of fibered faces for non-orientable 3-manifolds.
result The minimal stretch factor is asymptotically on the order of 1/g.

The study explores positive scalar curvature metrics on non-orientable manifolds and their covers.

problem Existence of positive scalar curvature metrics on non-orientable manifolds and their covers.
method Extends Schoen-Yau inductive descent approach to non-orientable manifolds.
result Examples of non-orientable manifolds with positive scalar curvature metrics on their orientation double covers but not on homotopy equivalent manifolds.

Analog of Kauffman bracket for non-orientable knots in thickened surface.

problem Defining an invariant for non-orientable knots in a non-orientable surface.
method Proposes an analog of the Kauffman bracket polynomial with modified sign rules.
result Polynomial is an isotopy invariant and independent of classical Kauffman for orientable covers.

Study on non-orientable hyperbolic 3-manifolds and their deformations.

problem Understanding the deformation space of non-orientable hyperbolic 3-manifolds.
method Computing the deformation space of pairs (M^3, Δ) and determining representations in Isom(H^3).
result Existence of deformations not realizable as pair deformations.

Study on non-orientable surfaces and inscribed rectangles in 4-manifolds.

problem Understanding non-orientable surfaces and their inscribed rectangles.
method Analyzing smooth and locally-flat non-orientable surfaces in 4-ball with specific knots, comparing results.
result Established differences between smooth and locally-flat non-orientable 4-genus of torus knots.

Study shows non-orientable manifolds restrict signature-changing metrics globally.

problem Global obstructions to signature-changing metrics on non-orientable manifolds.
method Explicit geometric constructions based on Möbius strip topology.
result Radical of signature-changing metrics cannot be everywhere transverse.

We classify all closed non-orientable P2-irreducible 3-manifolds having complexity up to 6 and we describe some having complexity 7. We show in particular that there is no such manifold with complexity less than 6, and that those having complexity 6 are precisely the 4 flat non-orientable ones and the filling of the Gi…

2002-11-05abs ↗pdf ↗

This paper covers non-orientable Euclidean manifolds B3 and B4, detailing their n-fold coverings.

problem Describing and calculating n-fold coverings of non-orientable Euclidean manifolds B3 and B4.
method Classifying subgroups in the fundamental groups π1(B3) and π1(B4) up to isomorphism, calculating numbers of subgroups and conjugacy classes for each isomorphism type.
result The numbers of non-equivalent n-fold coverings of each type of B3 and B4 are determined.

The construction of integer linking numbers of closed curves in a three-dimensional manifold usually appeals to the orientation of this manifold. We discuss how to avoid it constructing similar homotopy invariants of links in non-orientable manifolds.

2016-06-19abs ↗pdf ↗

We find conditions under which a non-orientable closed surface S embedded into an orientable closed 4-manifold X can be represented by a connected sum of an embedded closed surface in X and an unknotted projective plane in a 4-sphere. This allows us to extend the Gabai 4-dimensional light bulb theorem and the Auckly-Ki…

2018-08-26abs ↗pdf ↗

Paper introduces an invariant for knots in non-orientable manifolds, akin to Turaev's comultiplication.

problem Defining an invariant for pseudo-classical knots in non-orientable thickening of a non-orientable surface.
method Introducing an invariant ΔΔ that is an analogue of Turaev comultiplication, defined in terms of homotopy classes of loops on the surface.
result Analogous invariants to affine index polynomial for pseudo-classical knots in non-orientable manifolds.

New singularities and fibrations in non-orientable 4-manifolds.

problem Understanding singularities and fibrations in non-orientable 4-manifolds.
method Introducing MM-singularities and MM-fibrations, studying their handle decompositions and orientation double coverings.
result Relations among crosscap transpositions give rise to MM-fibrations on non-orientable 4-manifolds.

Non-orientable 4-manifolds are simple branched coverings of RP^4 and twisted S^3-bundles.

problem Characterizing non-orientable 4-manifolds as branched coverings.
method Showing that every closed connected non-orientable PL 4-manifold is a simple branched covering of $\RP^4$ and a twisted S3S^3-bundle.
result Non-orientable 4-manifolds are simple branched coverings of $\RP^4$ and twisted S3S^3-bundles, with specific conditions on the degree and branch set.

Study shows how any group can be fundamental of a non-orientable 4-manifold with exotic structure.

problem Realizing any finitely presented group as the fundamental group of a non-orientable 4-manifold with exotic structure.
method Performing a Gluck twist to obtain an exotic smooth structure, and using 2-covers to stabilize the structure.
result Any finitely presented group can be realized as the fundamental group of a non-orientable 4-manifold with exotic structure.

For a closed 4-manifold XX and a knot KK in the boundary of punctured XX, we define γX0(K)γ_X^0(K) to be the smallest first Betti number of non-orientable and null-homologous surfaces in punctured XX with boundary KK. Note that γS40γ^0_{S^4} is equal to the non-orientable 4-ball genus and hence γX0γ^0_X is a generalizati…

2014-11-18abs ↗pdf ↗

In this paper we deal with Seifert fibre spaces, which are compact 3-manifolds admitting a foliation by circles. We give a combinatorial description for these manifolds in all the possible cases: orientable, non-orientable, closed, with boundary. Moreover, we compute a potentially sharp upper bound for their complexity…

2017-04-21abs ↗pdf ↗

The paper studies quasimorphisms on density-preserving diffeomorphisms of the Möbius band.

problem Exploring quasimorphisms on groups of diffeomorphisms of non-orientable manifolds.
method Investigates the group of density-preserving diffeomorphisms on the Möbius band and shows the existence of unbounded quasimorphisms.
result The group of density-preserving diffeomorphisms on the Möbius band admits countably many unbounded quasimorphisms.

The paper studies extPin± ext{Pin}^{\pm}-structures on non-oriented 4-manifolds via Lefschetz fibrations.

problem Understanding extPin± ext{Pin}^{\pm}-structures on non-oriented 4-manifolds and Lefschetz fibrations.
method Extending work on orientable settings, the paper uses Lefschetz fibrations to analyze extPin± ext{Pin}^{\pm}-structures on non-orientable 4-manifolds and vector bundles.
result The paper provides existence results of extPin+ ext{Pin}^{+} and extPin ext{Pin}^--structures on closed non-orientable 4-manifolds and Lefschetz fibrations over the 2-sphere.

Through computer enumeration with the aid of topological results, we catalogue all 18 closed non-orientable P^2-irreducible 3-manifolds that can be formed from at most eight tetrahedra. In addition we give an overview as to how the 100 resulting minimal triangulations are constructed. Observations and conjectures are d…

2005-09-15abs ↗pdf ↗

By analogy with associative and co-associative cases we introduce a class of three-dimensional non-orientable submanifolds, of almost G2\mathrm{G}_2-manifolds, modelled on planes lying in a special G2\mathrm{G}_2-orbit. An application of the Cartan-Kähler theory shows that some three-manifold can be presented in this w…

2016-09-06abs ↗pdf ↗

We prove a new systolic volume lower bound for non-orientable n-manifolds, involving the stable 1-systole and the codimension 1 systole with coefficients in Z_2. As an application, we prove that Lusternik-Schnirelmann category and systolic category agree for non-orientable closed manifolds of dimension 3, extending our…

2005-04-01abs ↗pdf ↗

We investigate constraints on embeddings of a non-orientable surface in a 44-manifold with the homology of M×IM \times I, where MM is a rational homology 33-sphere. The constraints take the form of inequalities involving the genus and normal Euler class of the surface, and either the Ozsváth--Sazbó dd-invariants or …

2013-10-31abs ↗pdf ↗

We prove that fundamental groups of non-orientable 3-manifolds have a solvable conjugacy problem, and construct an algorithm. Together with our earlier work on the conjugacy problem in groups on orientable geometrizable 3-manifolds, all π1π_1 of (geometrizable) 3-manifolds have a solvable conjugacy problem. In corollar…

2012-02-19abs ↗pdf ↗

We classify all closed non-orientable P2-irreducible 3-manifolds with complexity up to 7, fixing two mistakes in our previous complexity-up-to-6 classification. We show that there is no such manifold with complexity less than 6, five with complexity 6 (the four flat ones and the filling of the Gieseking manifold, which…

2003-12-17abs ↗pdf ↗

The study determines Z2\mathbb{Z}_2-Thurston norms in Sol manifolds and embeds non-orientable surfaces.

problem Determining Z2\mathbb{Z}_2-Thurston norms in Sol manifolds and embedding non-orientable surfaces.
method Analyzing the action of torus maps on curve complexes and constructing incompressible surfaces.
result Determination of Z2\mathbb{Z}_2-Thurston norms and embeddability of non-orientable surfaces in Sol manifolds.

By considering non-orientable surfaces in the surgered manifolds, we show that the 10/3- and -10/3-Dehn surgeries on the 2-bridge knot 927=S(49,19)9_{27} = S(49,19) are not cosmetic, i.e., they give mutually non-homeomorphic manifolds. The knot is unknown to have no cosmetic surgeries by previously known results; in particular, …

2012-09-01abs ↗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 ↗

This paper studies Dirac operators on end-periodic spin manifolds of dimension at least 4. We provide a sufficient condition for such an operator to be Fredholm for a generic end-periodic metric; this condition is shown to be necessary in dimension 4. We make use of end-periodic Dirac operators to give an analytical in…

2007-02-09abs ↗pdf ↗

We investigate the complexity of finding an embedded non-orientable surface of Euler genus gg in a triangulated 33-manifold. This problem occurs both as a natural question in low-dimensional topology, and as a first non-trivial instance of embeddability of complexes into 33-manifolds. We prove that the problem is NP…

2016-02-25abs ↗pdf ↗

A census is presented of all closed non-orientable 3-manifold triangulations formed from at most seven tetrahedra satisfying the additional constraints of minimality and P^2-irreducibility. The eight different 3-manifolds represented by these 41 different triangulations are identified and described in detail, with part…

2003-11-07abs ↗pdf ↗

This paper calculates the non-orientable 4-genus for knots with 10 crossings.

problem Determining the non-orientable 4-genus for knots with a specific number of crossings.
method Calculating the minimal first Betti number of non-orientable surfaces smoothly embedded in a 4-ball with boundary the knot.
result The non-orientable 4-genus for knots with 10 crossings has been calculated.

Study curves in non-orientable surfaces with specific intersection properties.

problem Enumerate and understand curves in non-orientable surfaces with intersection constraints.
method Generalized construction of Malestein-Rivin-Theran to non-orientable surfaces.
result Lower bound for maximum number of curves in generic non-orientable surface.