Research
On-device research index

arXiv research

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.

169,291 papers · 148 categories

Trend · papers per month

12233546 · Jul 202619922001200920182026
48 results for Loose knots

A Legendrian or transverse knot in an overtwisted contact 3-manifold is non-loose if its complement is tight and loose if its complement is overtwisted. We define three measures of the extent of non-looseness of a non-loose knot and show they are distinct.

2013-12-19abs ↗pdf ↗

Loose Legendrian knots in rational homology spheres are Legendrian isotopic if they have the same classical invariants.

problem Classifying loose Legendrian knots in rational homology spheres.
method Combining Dymara's result on loose Legendrian knots and Eliashberg's classification of overtwisted contact structures.
result Loose Legendrian knots in rational homology spheres are Legendrian isotopic if and only if they have the same classical invariants.

We set forth a definition of hyperfinite knots. Loosely speaking, these are limits of certain sequences of knots with increasing crossing number. These limits exist in appropriate closures of quotient spaces of knots. We give examples of hyperfinite knots. These examples stem from an application of the Thermodynamic Li…

2006-07-07abs ↗pdf ↗

We prove a complete classification theorem for loose Legendrian knots in an oriented 3-manifold, generalizing results of Dymara and Ding-Geiges. Our approach is to classify knots in a 33-manifold MM that are transverse to a nowhere-zero vector field VV up to the corresponding isotopy relation. Such knots are called …

2014-05-22abs ↗pdf ↗

We show that the presence of a plastikstufe induces a certain degree of flexibility in contact manifolds of dimension 2n+1>3. More precisely, we prove that every Legendrian knot whose complement contains a "nice" plastikstufe can be destabilized (and, as a consequence, is loose). As an application, it follows in certai…

2012-11-16abs ↗pdf ↗

We describe various handle moves in contact surgery diagrams, notably contact analogues of the Kirby moves. As an application of these handle moves, we discuss the respective classifications of long and loose Legendrian knots.

2008-05-21abs ↗pdf ↗

We use monopole Floer homology for sutured manifolds to construct invariants of Legendrian knots in a contact 3-manifold. These invariants assign to a knot K in Y elements of the monopole knot homology KHM(-Y,K), and they strongly resemble the knot Floer homology invariants of Lisca, Ozsváth, Stipsicz, and Szabó. We pr…

2011-07-29abs ↗pdf ↗

Study on transverse knots and their neighborhoods, proving unique standard neighborhoods and destabilization results.

problem Understanding the structure and properties of transverse knots and their neighborhoods.
method Proves unique standard neighborhoods and structure theorems for non-loose Legendrian knots through destabilization results.
result Finds a manifold with infinite tight contact structures, up to contactomorphism, without Giroux torsion.

We prove that two Legendrian knots in a contact structure which is trivializable as a plane bundle are Legendrian isotopic provided that (1) they are isotopic as framed knots, (2) they have the same rotation number with respect to some parallelization of the contact structure, and (3) there is an overtwisted disk disjo…

2004-10-05abs ↗pdf ↗

We prove that each overtwisted contact structure has knot types that are represented by infinitely many distinct transverse knots all with the same self-linking number. In some cases, we can even classify all such knots. We also show similar results for Legendrian knots and prove a "folk" result concerning loose transv…

2010-12-16abs ↗pdf ↗

In this note, we define a new invariant of a Legendrian knot in a contact manifold using an open book decomposition supporting the contact structure. We define the support genus sg(L) of a Legendrian knot L in a contact 3-manifold (M, ξ) as the minimal genus of a page of an open book of M supporting the contact structu…

2009-05-14abs ↗pdf ↗

This is a survey on contact open books and contact Dehn surgery. The relation between these two concepts is discussed, and various applications are sketched, e.g. the monodromy of Stein fillable contact 3-manifolds, the Giroux-Goodman proof of Harer's conjecture on fibred links, construction of symplectic caps to filli…

2010-04-19abs ↗pdf ↗

Research shows that certain metric spaces cannot contain rigid structures and provides evidence for loose embeddings into Euclidean spaces.

problem The inability of certain metric spaces to contain rigid structures like regular simplices or equidistant sequences.
method Proof of non-embeddability of certain metric spaces into finite-dimensional Euclidean spaces and a local-to-global principle for loose embeddability.
result Compact Riemannian manifolds cannot contain arbitrarily large regular simplices or long equidistant sequences, suggesting loose embeddings into Euclidean spaces.

Quantum isometry groups extend to all countable metric spaces, and loose embeddings help understand metric space relationships.

problem Understanding the quantum isometry groups of all countable metric spaces.
method Defining and studying loose embeddability, showing that 0-dimensional compact metric spaces are generically loosely embeddable into the real line.
result 0-dimensional compact metric spaces are generically loosely embeddable into the real line.

A new quantum relation connects exceptional Lie algebras and knots.

problem Understanding the relationship between exceptional Lie algebras and quantum invariants of knots.
method Developed a two-parameter skein relation on trivalent graphs that specializes to exceptional Lie algebras.
result Found a new quantum exceptional polynomial that agrees with classical computations for knots and links.

We introduce a notion of "quasi-right-veering" for closed braids, which plays an analogous role to "right-veering" for open books. We show that a transverse link KK in a contact 3-manifold (M,ξ)(M,ξ) is non-loose if and only if every braid representative of KK with respect to every open book decomposition that supports …

2016-01-26abs ↗pdf ↗

Loose bounds found for least-norm interpolant in over-parameterized settings.

problem Failures of model-dependent generalization bounds for least-norm interpolation.
method Analysis of generalization performance of least-norm linear regressor in over-parameterized regime.
result Generalization bounds for least-norm interpolant can be very loose, even when true excess risk goes to zero.

New algorithm learns coordinated decisions in loosely-coupled multi-agent systems.

problem Learning coordinated decisions in multi-agent systems with sparse interactions.
method Multi-Agent Thompson Sampling (MATS) for multi-agent multi-armed bandits.
result MATS achieves sublinear regret and outperforms MAUCE on synthetic and real benchmarks.

We consider the structure learning problem for graphical models that we call loosely connected Markov random fields, in which the number of short paths between any pair of nodes is small, and present a new conditional independence test based algorithm for learning the underlying graph structure. The novel maximization …

2012-04-25abs ↗pdf ↗

Classifies Legendrian unknots in overtwisted S3S^3 contact structures.

problem Classifying Legendrian unknots in overtwisted contact structures on S3S^3.
method Contact isotopy, Thurston-Bennequin invariant, rotation number.
result Exactly two non-loose Legendrian unknots with specific invariants exist for each pair (n,±(n1))(n,\pm(n-1)).

This paper centers around two basic problems of topological coincidence theory. First, try to measure (with help of Nielsen and minimum numbers) how far a given pair of maps is from being loose, i.e. from being homotopic to a pair of coincidence free maps. Secondly, describe the set of loose pairs of homotopy classes. …

2006-06-01abs ↗pdf ↗

Study of contractible manifolds and their twists to determine if they are S4S^4.

problem Determine if a specific manifold is S4S^4 using twists and handlebody descriptions.
method Analyze two contractible manifolds, one Stein and one non-Stein, with non-trivial boundary mapping classes. Use a specific homotopy sphere to test if it is S4S^4.
result Show that a specific manifold is indeed S4S^4.

Given two maps f1 and f2 from the sphere Sm to an n-manifold N, when are they loose, i.e. when can they be deformed away from one another? We study the geometry of their (generic) coincidence locus and its Nielsen decomposition. On the one hand the resulting bordism class of coincidence data and the corresponding Niels…

2010-02-18abs ↗pdf ↗

The study explores Legendrian invariants and half Giroux torsion in contact structures.

problem Understanding Legendrian invariants and their behavior with half Giroux torsion.
method Analysis of Legendrian links with non-vanishing contact invariants and the study of half Giroux torsion.
result Null-homologous links with irreducible complements have non-loose Legendrian realizations with non-zero invariants.

InfoNCE objective is equivalent to ELBO in RPM, linking to self-supervised learning.

problem Improving self-supervised learning methods by connecting them to variational inference.
method Recognizing RPM and showing InfoNCE as a simplified lower bound on MI, equal to ELBO in infinite sample limit.
result The actual InfoNCE objective is equal to the ELBO (up to a constant) in the infinite sample limit.

Gossip-based actor-learner architectures improve deep reinforcement learning efficiency and scalability.

problem Stabilizing and scaling deep reinforcement learning through multi-simulator training.
method Gossip-based communication among actor-learners in a peer-to-peer topology, reducing synchronization.
result Gossip-based architectures outperform A2C in terms of robustness and sample efficiency.