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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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143285428570 · Jun 202019922001200920182026
48 results for first Postnikov invariant

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.

A countable CW complex KK is quasi-finite (as defined by A.Karasev) if for every finite subcomplex MM of KK there is a finite subcomplex e(M)e(M) such that any map f:AMf:A\to M, where AA is closed in a separable metric space XX satisfying XτKXτK, has an extension g:Xe(M)g:X\to e(M). Levin's results imply that none of the Ei…

2005-09-24abs ↗pdf ↗

Researchers classify quotients of lens spaces using linear actions and topological tools.

problem Classifying quotients of lens spaces under linear actions of (Z/p)2(\mathbb{Z}/p)^2.
method Postnikov towers and surgery theory.
result Quotients are classified up to homotopy by kk-invariants and up to homeomorphism by Pontrjagin classes.

Study Alexander polynomials of special alternating links and generalize Fox's conjecture.

problem Distinguish special alternating links up to isotopy using polynomial invariants.
method Combinatorial and discrete geometric properties of Alexander polynomials of special alternating links.
result Generalized Alexander polynomials of special alternating links can be expressed in terms of volumes of root polytopes of unimodular matrices.

The Temperley-Lieb algebra is a fundamental component of SU(2) topological quantum field theories. We construct chain complexes corresponding to minimal idempotents in the Temperley-Lieb algebra. Our results apply to the framework which determines Khovanov homology. Consequences of our work include semi-orthogonal deco…

2012-09-05abs ↗pdf ↗

We study smooth maps between smooth manifolds with only fold points as their singularities, and clarify the obstructions to the existence of such a map in a given homotopy class for certain dimensions. The obstructions are described in terms of characteristic classes, which arise as Postnikov invariants, and can be int…

2010-03-14abs ↗pdf ↗

Study homotopy types of 4-manifolds, finding decompositions and conditions for desuspension.

problem Determine homotopy types of double suspensions of 4-manifolds with 2-torsion.
method Use Postnikov square and analyze homology groups to find decompositions and conditions for desuspension.
result Homotopy decompositions of double suspensions as wedge sums of specific complexes.

The paper characterizes cohomotopy sets of specific manifolds.

problem Investigating cohomotopy sets of (n1)(n-1)-connected (2n+2)(2n+2)-manifolds.
method Combining Postnikov tower of spheres and homotopy decomposition of the reduced suspension space.
result Characterization of cohomotopy sets for n=2,3,4n=2,3,4.

The paper explores polytopes and their connections to knot theory and Floer homology.

problem Exploring polytopes and their dualities and triality relations.
method Theory of polytopes associated with bipartite graphs and trinities, extending into knot theory, 3-manifold topology, and Floer homology.
result Recent joint work with Kálmán extends the theory into contact topology and sutured Floer homology.

We give an alternative to Postnikov's homotopy classification of maps from 3-dimensional CW-complexes to homogeneous spaces G/H of Lie groups. It describes homotopy classes in terms of lifts to the group G and is suitable for extending the notion of homotopy to Sobolev maps. This is required for applications to variati…

2008-07-31abs ↗pdf ↗

The study tackles realisability of twisted homology classes and introduces new techniques in parametrised homotopy theory.

problem When a twisted homology class is realised by a submanifold.
method Introducing cobordism classes twisted by a coefficient system, defining a twisted Thom space, and constructing a parametrised Postnikov tower.
result A twisted homology class is realisable if and only if its Poincaré dual is the image of the twisted Thom class under a parametrised map.

We show that the small quantum product of the generalized flag manifold G/BG/B is a product operation on $H^*(G/B)\otimes \bR[q_1,..., q_l]$ uniquely determined by the fact that it is a deformation of the cup product on H(G/B)H^*(G/B), it is commutative, associative, graded with respect to °(qi)=4°(q_i)=4, it satisfies a certain…

2003-11-19abs ↗pdf ↗

For a closed topological nn--manifold KK and a map p:KBp:K\to B inducing an isomorphism π1(K)π1(B)π_1(K)\toπ_1(B), there is a canonicaly defined morphism b:Hn+1(B,K,L)S(K)b:H_{n+1}(B,K,\mathbb{L})\to \mathbb{S} (K), where L\mathbb{L} is the periodic simply-connected surgery spectrum and S(K)\mathbb{S} (K) is the topological structure set. We …

2014-09-10abs ↗pdf ↗

Geodesically equivalent Finsler metrics share invariant volume forms and first integrals.

problem Understanding shared properties of geodesically equivalent Finsler metrics.
method Computing first integrals as coefficients of a characteristic polynomial.
result Geodesically invariant functions are first integrals of geodesically equivalent Finsler metrics.

The first eigenvalue of invariant functions on toric Kähler manifolds has no critical points.

problem Analyzing the first eigenvalue of invariant functions on toric Kähler manifolds.
method Analyzing the function λ1Tλ_1^\mathbb{T} on the space of toric Kähler metrics and showing it has no critical points.
result The first eigenvalue of invariant functions on toric Kähler manifolds has no critical points.

Study Milnor invariants for covering links to distinguish certain links.

problem Distinguish links using Milnor invariants for covering links.
method Generalize Hartley and Murasugi's covering linkage invariants and use cobordism invariants.
result First non-vanishing Milnor invariants of a Brunnian link modulo 2 equals a sum of linking numbers of covering links.

In this paper, we define some polynomial invariants for virtual knots and links. In the first part we use Manturov's parity axioms to obtain a new polynomial invariant of virtual knots. This invariant can be regarded as a generalization of the odd writhe polynomial defined by the first author. The relation between this…

2013-01-09abs ↗pdf ↗

New research shows invariant networks can approximate any continuous function.

problem Can invariant networks approximate any continuous invariant function?
method Considered a general case where GG acts on Rn\mathbb{R}^n by permuting coordinates. Proved two main results: 1) GG-invariant networks are universal with high-order tensors, 2) higher-order tensors are necessary for universality with some groups.
result Invariant networks can approximate any continuous invariant function under certain conditions.

We generalise a theorem of Engman and Abreu--Freitas on the first invariant eigenvalue of non-negatively curved S1S^{1}-invariant metrics on CP1\mathbb{CP}^{1} to general toric Kähler metrics with non-negative scalar curvature. In particular, a simple upper bound of the first non-zero invariant eigenvalue for such metri…

2015-05-05abs ↗pdf ↗

The values that the first two Vassiliev invariants take on prime knots with up to fourteen crossings are considered. This leads to interesting fish-like graphs. Several results about the values taken on torus knots are proved.

2001-04-05abs ↗pdf ↗

We construct two knot invariants. The first knot invariant is a sum constructed using linking numbers. The second is an invariant of flat knots and is a formal sum of flat knots obtained by smoothing pairs of crossings. This invariant can be used in conjunction with other flat invariants, forming a family of invariants…

2011-09-14abs ↗pdf ↗

In this paper we give a re-normalization of the Reshetikhin-Turaev quantum invariants of links, by modified quantum dimensions. In the case of simple Lie algebras these modified quantum dimensions are proportional to the usual quantum dimensions. More interestingly we will give two examples where the usual quantum dime…

2007-11-27abs ↗pdf ↗

In this paper the notion of an M-th order invariant bilinear differential pairing is introduced and a formal definition is given. If the manifold has an AHS structure, then various first order pairings are constructed. This yields a classification of all first order invariant bilinear differential pairings on homogeneo…

2007-03-29abs ↗pdf ↗

A link L in the 3-sphere is called Brunnian if every proper sublink of L is trivial. In a previous paper, the first author proved that the restriction to Brunnian links of any Goussarov-Vassiliev finite type invariant of (n+1)-component links of degree<2n is trivial. The purpose of this paper is to study the first nont…

2005-10-25abs ↗pdf ↗

BGG-operators form sequences of invariant differential operators and the first of these is overdetermined. Interesting equations in conformal geometry described by these operators are those for Einstein scales, conformal Killing forms and conformal Killing tensors. We present a deformation procedure of the tractor conn…

2008-11-25abs ↗pdf ↗

We give a characterization of conformal classes realizing a compact manifold's Yamabe invariant. This characterization is the analogue of an observation of Nadirashvili for metrics realizing the maximal first eigenvalue, and of Fraser and Schoen for metrics realizing the maximal first Steklov eigenvalue.

2014-11-02abs ↗pdf ↗

Algorithm computes quantum invariants of 3-manifolds with bounded first Betti number.

problem Computing quantum invariants of 3-manifolds with bounded first Betti number is #P-hard.
method Fixed parameter tractable algorithm using dimension of first homology group as parameter.
result Algorithm is polynomial in the size of the input triangulation for 3-manifolds with bounded first Betti number.