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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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67133200266 · Jun 202019922001200920172026
48 results for Ramanujan Graphs

New bounds on diameters and generators for specific lattices and graphs.

problem Finding bounds on diameters and generators for arithmetic lattices and Ramanujan graphs.
method Analyzing arithmetic lattices from Eichler orders in quaternion algebras, applying techniques to definite quaternion algebras.
result Bounds on diameters and generators for arithmetic lattices and Ramanujan graphs.

The objectives of this article are three-fold. Firstly, we present for the first time explicit constructions of an infinite family of \textit{unbalanced} Ramanujan bigraphs. Secondly, we revisit some of the known methods for constructing Ramanujan graphs and discuss the computational work required in actually implement…

2019-10-08abs ↗pdf ↗

Proposes RBGP framework for efficient block sparse neural networks.

problem Efficiently exploit structured sparsity patterns for sparse neural networks on GPU.
method Uses Ramanujan Bipartite Graph Product to generate structured multi-level block sparse neural networks.
result Achieves 5-9x and 2-5x runtime gains over unstructured and block sparsity patterns respectively, while maintaining accuracy.

Derive new Euler-Ramanujan-type identities and infinite decompositions for zero mean curvature graphs in various spaces.

problem Derive new Euler-Ramanujan-type identities and infinite decompositions for zero mean curvature graphs in various spaces.
method Derive new Euler-Ramanujan-type identities and infinite decompositions for zero mean curvature graphs in various spaces.
result Derive new Euler-Ramanujan-type identities and infinite decompositions for zero mean curvature graphs in various spaces.

We show that a Born-Infeld soliton can be realised either as a spacelike minimal graph or timelike minimal graph over a timelike plane or a combination of both away from singular points. We also obtain some exact solutions of the Born-Infeld equation from already known solutions to the maximal surface equation. Further…

2017-02-21abs ↗pdf ↗

In this paper we study the matrix completion problem: Suppose XRnr×ncX \in {\mathbb R}^{n_r \times n_c} is unknown except for a known upper bound rr on its rank. By measuring a small number mnrncm \ll n_r n_c of elements of XX, is it possible to recover XX exactly with noise-free measurements, or to construct a good approxi…

2019-08-02abs ↗pdf ↗

Expander graphs have been a focus of attention in computer science in the last four decades. In recent years a high dimensional theory of expanders is emerging. There are several possible generalizations of the theory of expansion to simplicial complexes, among them stand out coboundary expansion and topological expand…

2014-08-27abs ↗pdf ↗

The tail of a sequence {Pn(q)}nN\{P_n(q)\}_{n \in \mathbb{N}} of formal power series in Z[[q]]\mathbb{Z}[[q]] is the formal power series whose first nn coefficients agree up to a common sign with the first nn coefficients of PnP_n. This paper studies the tail of a sequence of admissible trivalent graphs with edges colored nn o…

2013-08-11abs ↗pdf ↗

New conjectures link SU(r) Vafa-Witten invariants to Ramanujan's continued fractions.

problem Exploring new expressions for SU(r) Vafa-Witten partition functions.
method Combining S-duality, Gholampour-Thomas's theory, and Ramanujan's continued fractions.
result Conjectural expressions for SU(r) Vafa-Witten invariants in terms of theta functions and Seiberg-Witten invariants.

New cutoff phenomenon found for geodesic paths on hyperbolic manifolds.

problem Understanding the cutoff phenomenon for geodesic paths on hyperbolic manifolds.
method Spectral strategy and detailed spectral analysis of the spherical mean operator.
result Geodesic paths on compact hyperbolic manifolds exhibit cutoff for spatially localized initial conditions.

New volume functions for random hyperbolic surfaces link to spectral gaps.

problem Analyzing spectral gaps in random hyperbolic surfaces.
method Introduced new volume functions VgT(l)V_g^T(l), derived their asymptotic expansions, and linked them to spectral gaps.
result Coefficients in the asymptotic expansion of VgT(l)V_g^T(l) are Friedman-Ramanujan functions.

The height function of various surfaces decomposes into finite sums of scaled and translated versions of itself.

problem Decomposing the height function of different types of surfaces into simpler components.
method Using Euler-Ramanujan identities and Weierstrass-Enneper representation to decompose height functions of minimal, maximal, timelike minimal, and Born-Infeld surfaces.
result The height function of various surfaces can be expressed as a finite sum of scaled and translated versions of itself.

The paper shows how Scherk-type surfaces can be decomposed into helicoids.

problem Decomposing Scherk-type zero mean curvature surfaces.
method Using a special Euler-Ramanujan identity and Wick rotation, the paper expresses these surfaces as an infinite superposition of dilated helicoids and provides different finite decompositions.
result Scherk-type zero mean curvature surfaces can be expressed as an infinite superposition of dilated helicoids.

The tail of the colored Jones polynomial of an alternating link is a qq-series invariant whose first nn terms coincide with the first nn terms of the nn-th colored Jones polynomial. Recently, it has been shown that the tail of the colored Jones polynomial of torus knots give rise to Ramanujan type identities. In th…

2015-12-01abs ↗pdf ↗

Mock modular forms have found applications in numerous branches of mathematical sciences since they were first introduced by Ramanujan nearly a century ago. In this proceeding we highlight a new area where mock modular forms start to play an important role, namely the study of three-manifold invariants. For a certain c…

2019-12-17abs ↗pdf ↗

We conjecture that the stable Khovanov homology of torus knots can be described as the Koszul homology of an explicit non-regular sequence of quadratic polynomials. The corresponding Poincare series turns out to be related to the Rogers-Ramanujan identity.

2012-06-11abs ↗pdf ↗

In this work we present a new local to global criterion for proving a form of high dimensional expansion, which we term cosystolic expansion. Applying this criterion on Ramanujan complexes, yields for every dimension, an infinite family of bounded degree complexes with the topological overlapping property. This answer …

2015-10-03abs ↗pdf ↗

Rigidity is the property of a structure that does not flex. It is well studied in discrete geometry and mechanics, and has applications in material science, engineering and biological sciences. A bar-and-joint framework is a pair (G,p)(G,p) of graph GG together with a map pp of the vertices of GG into the Euclidean pla…

2020-01-20abs ↗pdf ↗

This article gives the foundations of the colored Jones polynomial for singular knots. We extend Masbum and Vogel's algorithm to compute the colored Jones polynomial for any singular knot. We also introduce the tail of the colored Jones polynomial of singular knots and use its stability properties to prove a false thet…

2017-05-06abs ↗pdf ↗

In this paper we study the common distance between points and the behavior of a constant length step discrete random walk on finite area hyperbolic surfaces. We show that if the second smallest eigenvalue of the Laplacian is at least 1/4, then the distances on the surface are highly concentrated around the minimal poss…

2017-12-29abs ↗pdf ↗

We develop the Ercolani-Sinha construction of SU(2) monopoles and make this effective for (a five parameter family of centred) charge 3 monopoles. In particular we show how to solve the transcendental constraints arising on the spectral curve. For a class of symmetric curves the transcendental constraints become a numb…

2006-01-20abs ↗pdf ↗

Motivated by community detection, we characterise the spectrum of the non-backtracking matrix BB in the Degree-Corrected Stochastic Block Model. Specifically, we consider a random graph on nn vertices partitioned into two equal-sized clusters. The vertices have i.i.d. weights {φu}u=1n\{ φ_u \}_{u=1}^n with second moment $Φ…

2016-09-08abs ↗pdf ↗

The lottery ticket hypothesis (Frankle and Carbin, 2018), states that a randomly-initialized network contains a small subnetwork such that, when trained in isolation, can compete with the performance of the original network. We prove an even stronger hypothesis (as was also conjectured in Ramanujan et al., 2019), showi…

2020-02-03abs ↗pdf ↗

The study explores autonomous systems and their connections to contact geometry and Frobenius manifolds.

problem Understanding the connections between autonomous systems and geometric structures.
method Investigation of the Darboux-Halphen-Ramanujan system, contact geometry, and Frobenius manifolds.
result Highlighting the role of contact geometry in autonomous systems.

The paper classifies affine minimal translation surfaces and finds their properties.

problem Classifying and understanding affine minimal translation surfaces.
method Using Weierstrass-Enneper formula and hodographic coordinate system.
result Classification and properties of affine minimal translation surfaces.

We compute the Moore-Witten regularized u-plane integral on CP^2, and we confirm their conjecture that it is the generating function for the SO(3)-Donaldson invariants of CP^2. We prove this conjecture using the theory of mock theta functions and harmonic Maass forms. We also derive further such generating functions fo…

2008-08-11abs ↗pdf ↗

The colored Jones polynomial is a qq-polynomial invariant of links colored by irreducible representations of a simple Lie algebra. A qq-series called a tail is obtained as the limit of the sl2\mathfrak{sl}_2 colored Jones polynomials {Jn(K;q)}n\{J_n(K;q)\}_n for some link KK, for example, an alternating link. For the $\mathf…

2016-12-07abs ↗pdf ↗

The non-abelian Hodge correspondence identifies complex variations of Hodge structures with certain Higgs bundles. In this work we analyze this relationship, and some of its ramifications, when the variations of Hodge structures are determined by a (complete) one-dimensional family of compact Calabi-Yau manifolds. This…

2019-11-15abs ↗pdf ↗

Explicitly constructed 3XOR instances hard for Sum-of-Squares hierarchy.

problem Hard instances for Sum-of-Squares hierarchy.
method Based on high-dimensional expanders (LSV complexes), using cosystolic expansion and local isoperimetric inequality.
result Constructs explicit 3XOR instances hard for O(logn)O(\sqrt{\log n}) levels of Sum-of-Squares hierarchy.

Study compares two methods to extend Z^\widehat{Z} invariants, finding incompatibility for Brieskorn spheres.

problem Comparing two methods to extend Z^\widehat{Z} invariants for 3-manifolds.
method Two prescriptions: regularized +1/r+1/r-surgery combined with false-mock modular conjecture, and resurgence-based construction.
result Incompatibility found between the two prescriptions for some Brieskorn spheres.

Line graph transformation aids graph isomorphism tests by excluding challenging graph properties.

problem Limited theoretical understanding of line graph transformation's impact on GNN models.
method Examined CFI and strongly regular graphs, showing line graph transformation helps WL tests distinguish these graphs.
result Line graph transformation aids WL tests in distinguishing challenging graph properties.

Proposes MGMN for end-to-end graph similarity learning.

problem Lack of cross-level interactions in graph similarity learning.
method Multi-level graph matching network (MGMN) combining node-graph matching and siamese graph neural networks.
result MGMN outperforms state-of-the-art models on graph-graph classification and regression tasks.

MxPool learns graph features from diverse graphs using a hierarchical structure.

problem Learning graph features from diverse graphs with varying properties and sizes.
method MxPool uses a multiplex structure with multiple graph convolution/pooling networks in a hierarchical learning structure.
result MxPool outperforms state-of-the-art methods on graph classification benchmarks.

Quasi-transitive graphs quasi-isometric to planar graphs can be upgraded to Cayley graphs.

problem Quasi-transitive graphs quasi-isometric to planar graphs need to be upgraded to Cayley graphs.
method Upgrading a planar graph to a Cayley graph.
result Quasi-transitive graphs quasi-isometric to planar graphs can be upgraded to Cayley graphs.