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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.

168,742 papers · 148 categories

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36912 · Oct 201819922001200920172026
48 results for prime theta-curves

We prove a folklore theorem of W. Thurston which provides necessary and sufficient conditions for primality of a certain class of theta-curves. Namely, a theta-curve in the 3-sphere with an unknotted constituent knot U is prime if and only if lifting the third arc of the theta-curve to the double branched cover over U …

2015-09-25abs ↗pdf ↗

Determinants of theta curves and symmetric graphs are studied.

problem Understanding the determinants of theta curves and symmetric graphs.
method Combinatorial approach using Kirchhoff's Matrix Tree Theorem and spanning tree enumeration.
result The determinant of a simple theta curve is the product of the determinants of its constituent knots.

The normalized Yamada polynomial is a polynomial invariant in variable A for theta-curves. In this work, we show that the coefficients of the power series obtained from this polynomial by the substitution A=e^x=1+x+x^2/2+x^3/6+... are finite-type invariants for theta-curves although the coefficients of original polynom…

2001-04-18abs ↗pdf ↗

A region crossing change at a region of a spatial-graph diagram is a transformation changing every crossing on the boundary of the region. In this paper, it is shown that every spatial graph consisting of theta-curves can be unknotted by region crossing changes.

2019-10-27abs ↗pdf ↗

We study the minimal crossing number c(K1#K2)c(K_{1}\# K_{2}) of composite knots K1#K2K_{1}\# K_{2}, where K1K_1 and K2K_2 are prime, by relating it to the minimal crossing number of spatial graphs, in particular the 2n2n-theta curve θK1,K2nθ_{K_{1},K_{2}}^n that results from tying nn of the edges of the planar embedding of the $2n…

2017-09-15abs ↗pdf ↗

In this paper, we study on knots and closed incompressible surfaces in the 3-sphere via Morse functions. We show that both of knots and closed incompressible surfaces can be isotoped into a "related Morse position" simultaneously. As an application, we have following results. *Smallness of Montesinos tangles with lengt…

2005-03-18abs ↗pdf ↗

Study on knot properties, showing relation between unknotting and crossing numbers.

problem Relations between unknotting and crossing numbers of spatial embeddings.
method Analyzes handcuff-graphs and theta curves, extends known results to handlebody-knots.
result Characterizes handlebody-knots satisfying the equality between unknotting and crossing numbers.

For a 3-dimensional manifold M3M^3, its complexity c(M3)c(M^3), introduced by S.Matveev, is the minimal number of vertices of an almost simple spine of M3M^3; in many cases it is equal to the minimal number of tetrahedra in a singular triangulation of M3M^3. An approach to estimating c(M3)c(M^3) from below for total spaces o…

2001-03-26abs ↗pdf ↗

The main purpose of this note is the study of the total space of a holomorphic Lie algebroid EE. The paper is structured in three parts. In the first section we briefly introduce basic notions on holomorphic Lie algebroids. The local expressions are written and the complexified holomorphic bundle is introduced. The se…

2016-05-26abs ↗pdf ↗

Kirby and Lickorish showed that every knot in the 3-sphere is concordant to a prime knot, equivalently, every concordance class contains a prime knot. We prove here that their result can be strengthened: Every knot in the 3-sphere is invertibly concordant to a prime knot. A consequence is that every double concordance …

2000-03-05abs ↗pdf ↗

This is the first in a series of four papers wherein we enumerate all prime alternating knots and links. In this first paper, we introduce four operators on knots and show that, when used according to very simple rules on the prime alternating knots of n crossings, the set of all prime alternating knots of n+1 crossing…

2002-11-21abs ↗pdf ↗

This is the third paper in a series devoted to enumerating the prime alternating knots and links. This paper establishes a method for enumerating the prime alternating links. It is shown that one may choose any prime alternating link diagram of a given minimal crossing size and by applications of just two operators (T …

2002-11-28abs ↗pdf ↗

Decomposing knots and links into tangles is a useful technique for understanding their properties. The notion of prime tangles was introduced by Kirby and Lickorish in [3]; Lickorish proved [5] that by summing prime tangles one obtains a prime link. In a similar spirit, summing two prime alternating tangles will produc…

2019-06-15abs ↗pdf ↗

Expanding on prime knots with 6 or less mosaic tiles, this paper analyzes those with 7 tiles.

problem Determining the tile number and space-efficiency for prime knots with mosaic number 7.
method Extending the methods of Heap and Knowles (2017) to include prime knots with mosaic number 7.
result Identifying the possible tile numbers and space-efficient layouts for all prime knots with mosaic number 7.

We describe a method for generating minimal hard prime surface-link diagrams. We extend the known examples of minimal hard prime classical unknot and unlink diagrams up to three components and generate figures of all minimal hard prime surface-unknot and surface-unlink diagrams with prime base surface components up to …

2017-06-28abs ↗pdf ↗

We prove that a prime knot K is not determined by its p-fold cyclic branched cover for at most two odd primes p. Moreover, we show that for a given odd prime p, the p-fold cyclic branched cover of a prime knot K is the p-fold cyclic branched cover of at most one more knot K' non equivalent to K. To prove the main theor…

2007-02-26abs ↗pdf ↗

New tool lassos connects virtual and surface link diagrams, changing primeness rules.

problem Establishing a new correspondence between virtual and surface link diagrams.
method Using a new tool called lassos, establishing a new correspondence between cellular link diagrams on closed surfaces and equivalence classes of virtual link diagrams.
result Traditional primeness for virtual links is stricter than for links in thickened surfaces.

The paper proves a generalized Kauffman-Harary conjecture for prime determinant links.

problem Proving a generalized Kauffman-Harary conjecture for prime determinant links.
method Using Fox colorings and properties of reduced alternating diagrams.
result For every pair of distinct arcs in a prime determinant link, there exists a Fox coloring that distinguishes them.

We show that the Frölicher spectral sequence of a complex parallelizable solvmanifold is degenerate at E2E_{2}-term. For a semi-direct product $G=\C^{n}\ltimes_φN$ of Lie-groups with lattice Γ=ΓΓΓ=Γ^{\prime}\ltimes Γ^{\prime\prime} such that NN is a nilpotent Lie-group with a left-invariant complex structure and φφ is …

2012-10-09abs ↗pdf ↗

Menasco showed that a non-split, prime, alternating link that is not a 2-braid is hyperbolic in S3S^3. We prove a similar result for links in closed thickened surfaces S×IS \times I. We define a link to be fully alternating if it has an alternating projection from S×IS\times I to SS where the interior of every complemen…

2018-02-15abs ↗pdf ↗

The paper finds at least four prime closed characteristics on star-shaped hypersurfaces in 8D space.

problem Finding prime closed characteristics on compact star-shaped hypersurfaces in 8D space.
method Proved existence of at least four prime closed characteristics for non-degenerate C3C^3 compact star-shaped hypersurfaces in R8\mathbb{R}^{8} without prime closed characteristics of Maslov-type index -1.
result Existence of at least four prime closed characteristics on compact star-shaped hypersurfaces in R8\mathbb{R}^{8}.

We construct prime amphicheiral knots that have free period 2. This settles an open question raised by the second named author, who proved that amphicheiral hyperbolic knots cannot admit free periods and that prime amphicheiral knots cannot admit free periods of order >2.

2018-04-09abs ↗pdf ↗

pPCA speeds up PCA by priming initial estimates for faster, more accurate results.

problem Improving the speed and accuracy of principal component analysis (PCA).
method pPCA is a two-step algorithm: first, an approximate-PCA method primes the data, then exact PCA is applied in the span of the initial estimate.
result pPCA improves accuracy significantly with a small computational cost, outperforming other methods across various datasets.