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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.

168,657 papers · 148 categories

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20395978 · May 202619922001200920172026
48 results for Schur Decomposition

New algorithm learns ReLU networks efficiently using Schur polynomials.

problem PAC learning a linear combination of ReLU activations under Gaussian distribution.
method Uses tensor decomposition and Schur polynomials to identify and analyze higher-order moments.
result Near-optimal sample and computational complexity for learning ReLU networks.

The paper defines new types of positivity and proves properties of Schur forms for vector bundles.

problem Defining and characterizing new types of positivity for vector bundles.
method Introducing and characterizing two types of strongly decomposable positivity, proving properties of Schur forms.
result Schur forms of strongly decomposable positive vector bundles are positive or weakly positive, answering a question of Griffiths.

In this paper, we study a general almost Schur Lemma on pseudo-Hermitian (2n+1)-manifolds (M,J,θ)(M,J,θ) for n2n\geq2. When the equality of almost Schur inequality holds, we derive the contact form θθ is pseudo-Einstein and the pseudo-Hermitian scalar curvature is constant.

2014-05-13abs ↗pdf ↗

Quantifies Schur's theorem for curves in CAT(k) spaces.

problem Quantifying Schur's comparison theorem for curves in CAT(k) spaces.
method Comparison formula for curves in model planes, curvature measures, moment arm, and Reshetnyak's theorem.
result Sharpens and extends classical arm and bow lemmas and Riemannian analogues.

New unoriented versions of Schur and Bogomolov multipliers for finite groups.

problem Defining and analyzing unoriented versions of Schur and Bogomolov multipliers.
method Using cohomology groups and quotient groups to define unoriented multipliers.
result Triviality of unoriented Bogomolov multiplier for certain groups, nontriviality for others.

Let X=G/P be cominuscule rational homogeneous variety. (Equivalently, X admits the structure of a compact Hermitian symmetric space.) We say a Schubert class [S] is Schur rigid if the only irreducible subvarieties Y of X with homology class [Y] = r [S], for an integer r, are Schubert varieties. Robles and The identifie…

2012-03-01abs ↗pdf ↗

We describe an iterative construction of Lagrangian tori in the complex Grassmannian Gr(k,n)\operatorname{Gr}(k,n), based on the cluster algebra structure of the coordinate ring of a mirror Landau-Ginzburg model proposed by Marsh-Rietsch. Each torus comes with a Laurent polynomial, and local systems controlled by the kk-va…

2019-10-24abs ↗pdf ↗

Schur theorem proven for weakly Landsberg Finsler metrics.

problem Proving the Schur theorem for a specific class of Finsler metrics.
method Using the Ricci curvature and properties of the mean Landsberg tensor, the theorem is proven for weakly Landsberg metrics.
result For weakly Landsberg Finsler metrics, the Ricci scalar must be constant.

Study framizations of algebras using Schur--Weyl duality and tied braids.

problem Understanding framizations of algebras and their connections to quantum groups.
method Developing a general setting for framizations of algebras, including Yokonuma--Hecke and tied braids.
result Obtained Schur--Weyl duality for various algebras, including new framizations.

We make a new attempt at the recently suggested program to express knot polynomials through topological vertices, which can be considered as a possible approach to the tangle calculus: we discuss the Macdonald deformation of the relation between the convolution of two topological vertices and the HOMFLY-PT invariant of…

2019-05-01abs ↗pdf ↗

Let L be a link in a thickened annulus. We show that its sutured annular Khovanov homology carries an action of the exterior current algebra of the Lie algebra sl_2. When L is an m-framed n-cable of a knot K in the three-sphere, its sutured annular Khovanov homology carries a commuting action of the symmetric group S_n…

2015-05-17abs ↗pdf ↗

Researchers prove a stability result for a 3-sphere inequality, extending previous work.

problem Quantitative stability of nonlinear Yamabe-type inequalities on the 3-sphere.
method Proved a two-term refinement of the Schur lemma inequality in the conformal class of the 3-sphere.
result Deduced quantitative stability of an entire family of nonlinear Yamabe-type inequalities.

A new method for efficient portfolio optimization using graph structures.

problem Optimizing portfolio weights while reducing computational complexity.
method Hierarchical graph structures and Schur complement method.
result Optimal portfolio weights can be computed efficiently by inverting small submatrices.

The Schur's theorem of antiholomorphic type is proved for arbitrary almost Hermitian manifolds, namely: If a connected almost Hermitian manifold of dimension greater or equal to 6 is of pointwise constant antiholomorphic sectional curvature, then this curvature is a global constant.

2011-08-25abs ↗pdf ↗

We define a map from second quandle homology to the Schur multiplier and examine its properties. Furthermore, we express the second homology of Alexander quandles in terms of exterior algebras. Additionally, we present a self-contained proof of its structure and provide some computational examples.

2018-12-11abs ↗pdf ↗

Constructs new topological theories in 2D not fitting standard axioms.

problem Developing new topological theories in 2D that don't conform to traditional axioms.
method Universal construction by Blanchet et al., Kronecker's characterization, field extension, Hankel matrices, Schur polynomials, and foam evaluation.
result Introduction of non-multiplicative theories and classification over finite-dimensional state spaces.

In this short note we establish an integral geometric inequality in a smooth metric measure space of the nonnegative Bakry-Émery Ricci curvature. This result can be regarded as a mild generalization of the almost Schur theorem due to De Lellis and Topping (Calc. Var., DOI: 10.1007/s00526-011-0413-z).

2011-05-11abs ↗pdf ↗

Schur's lemma states that every Einstein manifold of dimension n3n\geq 3 has constant scalar curvature. Here (M,g)(M,g) is defined to be Einstein if its traceless Ricci tensor $$\Rico:=\Ric-\frac{R}{n}g$$ is identically zero. In this short note we ask to what extent the scalar curvature is constant if the traceless Ricci …

2010-03-18abs ↗pdf ↗

Somewhat unexpectedly, the study of the family of twisted knots revealed a hidden structure behind exclusive Racah matrices Sˉ\bar S, which control non-associativity of the representation product in a peculiar channel RRˉRRR\otimes \bar R \otimes R \longrightarrow R. These Sˉ\bar S are simultaneously symmetric and orthogo…

2019-06-24abs ↗pdf ↗

The paper finds new inequalities for convex polygons.

problem Finding precise inequalities for convex polygons.
method Analytic isoperimetric inequalities based on Schur convex functions, followed by Bonnesen-style and inverse Bonnesen-style inequalities.
result Sharp discrete isoperimetric inequalities for planar convex polygons.

This paper introduces Schur-constant equilibrium distribution models of dimension n for arithmetic non-negative random variables. Such a model is defined through the (several orders) equilibrium distributions of a univariate survival function. First, the bivariate case is considered and analyzed in depth, stressing the…

2017-09-28abs ↗pdf ↗

Spatial statisticians and quantitative investors use the same mathematical object: a Schur complement, damped by one parameter.

problem The Schur complement is used in both spatial modeling and portfolio allocation, but the parameters are different.
method The Schur complement is interpreted as reliability shrinkage of a conditional Gaussian.
result The Schur complement is the same in both applications.

The paper proves positivity of characteristic forms for certain vector bundles.

problem Characterizing positivity conditions for vector bundles.
method Operator theory, pushforward identities, and differential forms.
result Schur polynomials in Chern forms of Nakano and Griffiths positive vector bundles are positive as differential forms.

Preprint proves quantum coideal Schur-Weyl duality and generalizes Jones-Wenzl projectors.

problem Quantum coideal Schur-Weyl duality and Jones-Wenzl projectors in type B/D.
method Combinatorial proofs and functional analytic arguments.
result Explicit proof of quantum coideal Schur-Weyl duality and generalization of Jones-Wenzl projectors.

Fix a finite group GG and a conjugacy invariant subset CGC\subseteq G. Let ΣΣ be an oriented surface, possibly with punctures. We consider the question of when two homomorphisms π1(Σ)Gπ_1(Σ) \to G taking punctures into CC are equivalent up to an orientation preserving diffeomorphism of ΣΣ. We provide an answer to this …

2017-09-10abs ↗pdf ↗

The paper optimizes policies constrained to Schur stabilizing controllers using a Newton-type algorithm.

problem Optimizing policies under linear constraints in control systems.
method Newton-type algorithm on a manifold of Schur stabilizing controllers with a Riemannian metric.
result Local convergence guarantees for the Newton-type algorithm without relying on exponential mapping or retractions.