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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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48 results for bridge index

The study of 2-bridge knots reveals a linear average braid index as crossing number increases.

problem Understanding the distribution of braid indices in 2-bridge knots.
method Analyzing the asymptotic behavior of braid indices for fixed crossing numbers.
result The average braid index of 2-bridge knots of crossing number cc is asymptotically $ rac{c}{3}+ rac{11}{9}$.

An upper bound of the superbridge index of the connected sum of two knots is given in terms of the braid index of the summands. Using this upper bound and minimal polygonal presentations, we give an upper bound in terms of the superbridge index and the bridge index of the summands when they are torus knots. In contrast…

2000-01-15abs ↗pdf ↗

The paper explores knots with equal bridge and braid index, conjecturing they have a unique equilibrium state.

problem Identifying and characterizing knots with equal bridge and braid index.
method Heuristic explanation and numerical exploration of conjectured properties.
result Identification of BB knots in various knot families and an exponential growth in the number of BB knots with increasing crossing number.

We give the bridge indices for 11-crossing prime knots and give a minimal bridge projection for each of these knots. The results on the indices may be easily summarized: all of these knots that are not rational knots or Montesinos knots have bridge index three.

2012-08-21abs ↗pdf ↗

It is known that there are only finitely many knots with super bridge index 3. Jin and Jeon have provided a list of possible such candidates. However, they conjectured that the only knots with super bridge index 3 are trefoil and the figure eight knot. In this paper, we prove that the 525_2 knot and the 626_2 knot are …

2012-09-14abs ↗pdf ↗

New method calculates bridge indices of spatial graphs using diagram colorings and Wirtinger number.

problem Calculating bridge indices for spatial graphs efficiently.
method Extending Wirtinger number to spatial graphs, implementing Python algorithm, combining algebraic structures and clasping techniques.
result Exact bridge indices for almost unknotted graphs of large bridge index.

A closed, orientable, splitting surface in an oriented 33-manifold is a topologically minimal surface of index nn if its associated disk complex is (n2)(n-2)-connected but not (n1)(n-1)-connected. A critical surface is a topologically minimal surface of index 22. In this paper, we use an equivalent combinatorial definit…

2016-02-17abs ↗pdf ↗

If a graph is in bridge position in a 3-manifold so that the graph complement is irreducible and boundary irreducible, we generalize a result of Bachman and Schleimer to prove that the complexity of a surface properly embedded in the complement of the graph bounds the graph distance of the bridge surface. We use this r…

2017-06-01abs ↗pdf ↗

Given a connected cobordism between two knots in the 3-sphere, our main result is an inequality involving torsion orders of the knot Floer homology of the knots, and the number of local maxima and the genus of the cobordism. This has several topological applications: The torsion order gives lower bounds on the bridge i…

2019-04-04abs ↗pdf ↗

We provide a new proof of the following results of H. Schubert: If K is a satellite knot with companion J and pattern L that lies in a solid torus T in which it has index k, then the bridge numbers satisfy the following: 1) The bridge number of K is greater than or equal to the product of k and the bridge number of J; …

2001-11-02abs ↗pdf ↗

We describe a method of encoding various types of link diagrams, including those with classical, flat, rigid, welded, and virtual crossings. We show that this method may be used to encode link diagrams, up to equivalence, in a notation whose length is a cubic function of the number of 'riser marks'. For classical knots…

2012-08-01abs ↗pdf ↗

New procedures connect braid charts, triplane diagrams, and braid movies for knotted surfaces.

problem Understanding the braid index and bridge index of knotted surfaces in 4D.
method Introducing rainbow diagrams and new procedures for passing among triplane diagrams, braid movies, and braid charts.
result Inequalities relating braid index and bridge index of 2-knots are obtained.

Following Riley's work, for each 2-bridge link K(r)K(r) of slope $r\in\QQ$ and an integer or a half-integer nn greater than 1, we introduce the {\it Heckoid orbifold $\orbs(r;n)$} and the {\it Heckoid group $\Hecke(r;n)=π_1(\orbs(r;n))$ of index nn for K(r)K(r)}. When nn is an integer, $\orbs(r;n)$ is called an {\it eve…

2012-06-19abs ↗pdf ↗

The bridge index and superbridge index of a knot are important invariants in knot theory. We define the bridge map of a knot conformation, which is closely related to these two invariants, and interpret it in terms of the tangent indicatrix of the knot conformation. Using the concepts of dual and derivative curves of s…

2012-05-23abs ↗pdf ↗

Two new invariants that are closely related to Milnor's curvature-torsion invariant are introduced. The first, the spiral index of a knot, captures the minimum number of maxima among all knot projections that are free of inflection points. This invariant is closely related to both the bridge and braid index of the knot…

2009-03-03abs ↗pdf ↗

A differential geometric characterization of the braid-index of a link is found. After multiplication by 2pi, it equals the infimum of the sum of total curvature and total absolute torsion over holonomic representatives of the link. Upper and lower bounds for the infimum of total curvature over holonomic representative…

1999-05-07abs ↗pdf ↗

The paper diagnoses factor-model pricing errors using characteristic axes and bridge-alpha curves.

problem Tackles systematic sign reversals and overcorrections in factor-model pricing errors.
method Extends cap-axis integral diagnostic to characteristic axes, measures pricing errors as bridge-alpha curves, and uses a predetermined characteristic order to generate zero-curve restrictions.
result Axis-level pricing errors are nearly orthogonal to maximum-Sharpe gains, showing significant sign reversals and overcorrections.

Contact round surgeries on (S3,ξst)(\mathbb{S}^3,ξ_{st}) help in constructing and understanding contact 3-manifolds.

problem Constructing contact 3-manifolds using Legendrian surgeries.
method Introducing contact round surgeries of indices 1 and 2, and associating them with surgery diagrams.
result Every closed connected contact 3-manifold can be obtained by a sequence of contact round surgeries on Legendrian knots in (S3,ξst)(\mathbb{S}^3,ξ_{st}).

We describe a correspondence between augmentations and certain representations of the knot group. The correspondence makes the 2-variable augmentation polynomial into a generalization of the classical AA-polynomial. It also associates to an augmentation a rank, which is bounded by the bridge number and shares its beha…

2013-10-28abs ↗pdf ↗

The study explores relations between various knot invariants.

problem Understanding the relationships between different knot invariants.
method Defined a relation between maps from knot types to sets X and Y, and determined specific relations for various knot invariants.
result Determined relations between crossing number, unknotting number, bridge number, braid index, genus, and canonical genus.

We investigate the statistics of records in a random sequence {xB(0)=0,xB(1),,xB(n)=xB(0)=0}\{x_B(0)=0,x_B(1),\cdots, x_B(n)=x_B(0)=0\} of nn time steps. The sequence xB(k)x_B(k)'s represents the position at step kk of a random walk `bridge' of nn steps that starts and ends at the origin. At each step, the increment of the position is a random ju…

2015-05-22abs ↗pdf ↗

A smooth five-dimensional s-cobordism becomes a smooth product if stabilized by a finite number n of S2xS2x[0,1]S^2xS^2x[0,1]'s. We show that for amenable fundamental groups, the minimal n is subextensive in covers, i.e., n(cover)/index(cover) has limit 0. We focus on the notion of sweepout width, which is a bridge between 4-di…

2015-03-18abs ↗pdf ↗

The paper diagnoses factor models using characteristic axes and zero-curve restrictions.

problem Tackles systematic sign reversals and overcorrections in factor model pricing errors.
method Extends cap-axis integral diagnostic to general characteristic axes, measuring pricing errors as bridge-alpha curves.
result Axis-level pricing errors are nearly orthogonal to maximum-Sharpe gains, showing systematic sign reversals and overcorrections.

A spring-block chain placed on a running conveyor belt is considered for modeling stylized facts observed in the dynamics of stock indexes. Individual stocks are modeled by the blocks, while the stock-stock correlations are introduced via simple elastic forces acting in the springs. The dragging effect of the moving be…

2014-09-04abs ↗pdf ↗

Neural Index Policy for multi-action bandits with heterogeneous budgets.

problem Real-world settings often involve multiple interventions with heterogeneous costs and constraints, breaking classical assumptions.
method Introduces a Neural Index Policy (NIP) that learns to assign budget-aware indices to arm-action pairs using a neural network and differentiable knapsack layer.
result Empirically achieves near-optimal performance while strictly enforcing heterogeneous budgets and scaling to hundreds of arms.

This paper diagnoses factor-model pricing errors using a new method.

problem Measuring pricing errors in factor models with general characteristic axes.
method Developed a method to measure factor-model pricing errors as bridge-alpha curves, using a predetermined characteristic order and prefix portfolios.
result Adding a counterpart factor flips the curve's sign on every axis, but only HML and CMA overcorrect enough to be rejected.

Study improves retail demand forecasting by integrating macroeconomic data.

problem Lack of accurate demand forecasting due to incomplete data.
method Enriched time series data with macroeconomic variables; compared regression and machine learning models.
result Improved accuracy in predicting retail demand through comprehensive data integration.

THRML uses energy-based models for index tracking, reducing portfolio tracking error and improving returns.

problem NP-hard combinatorial optimization in portfolio optimization under cardinality constraints.
method THRML reformulates index tracking as probabilistic inference on an Ising Hamiltonian, using GPU-accelerated block Gibbs sampling.
result THRML achieves 4.31 percent annualized tracking error compared to 5.66-6.30 percent for baselines, with 128.63 percent total return.