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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.

168,695 papers · 148 categories

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91181272362 · Jun 202019922001200920172026
48 results for closed form

If a closed 3-manifold M supports a closed, nonsingular, irrational 1-form which linearly deforms into contact forms, then M supports a K-contact form. On the 3-torus, a closed nonsingular 1-form deforms linearly into contact forms if and only if it is a fibration 1-form. on any other 2-torus bundle over the circle, ev…

2008-12-17abs ↗pdf ↗

The n-dimensional torus is uniquely characterized by specific harmonic forms.

problem Characterizing the n-dimensional torus via harmonic forms.
method Analyzing closed 1-forms on the torus to determine unique properties.
result The n-dimensional torus is the unique manifold supporting a linearly independent set of (n-1) closed 1-forms whose product determines a non-zero cohomological class.

Alternative closed-form formula for spread call option prices under log-normal models.

problem Valuation of spread call options under log-normal models.
method Developed an alternative closed-form formula for spread call option prices.
result Our formula performs better for certain range of model parameters than existing closed-form formula.

We consider the closed orbit structure of generic gradient flows of Morse closed 1-forms. The torsion of a chain homotopy equivalence between the Novikov complex and the completed simplicial chain complex of the universal cover detects the eta function of the flow. We extend this result to arbitrary Morse closed 1-form…

2000-09-06abs ↗pdf ↗

Naz and Chaudhry [3] established multiple closed-form solutions for the basic Lucas-Uzawa model. According to Boucekkine and Ruiz-Tamarit [1] and Chilarescu [2] unique closed-form solutions exist for the basic Lucas-Uzawa model. We equate expressions for variables h(t) and u(t). We provide here condition for the unique…

2017-12-06abs ↗pdf ↗

Let (M,I,J,K)(M,I,J,K) be a hyperkaehler manifold, dimRM=4n\dim_\R M =4n. We study positive, Dolbeault-closed (2p,0)(2p,0)-forms on (M,I)(M,I). These forms are quaternionic analogues of the positive (p,p)(p,p)-forms. We construct an injective homomorphism mapping Dolbeault-closed (2p,0)(2p,0)-forms to closed (n+p,n+p)(n+p,n+p)-forms, and positive $(2p,…

2008-01-12abs ↗pdf ↗

Study topological properties of foliations induced by closed 1-forms on orbifolds.

problem Characterize the topology of foliation leaves induced by closed 1-forms on orbifolds.
method Establish criteria for the compactness of foliation leaves and extend a topological result to orbifolds.
result Criteria for the compactness and coexistence of foliation leaves are established.

We discuss controlled connectivity properties of closed 1-forms and their cohomology classes and relate them to the simple homotopy type of the Novikov complex. The degree of controlled connectivity of a closed 1-form depends only on positive multiples of its cohomology class and is related to the Bieri-Neumann-Strebel…

2002-03-27abs ↗pdf ↗

The paper suggests new topological lower bounds for the number of zeros of closed 1-forms within a given cohomology class. The main new technical tool is the deformation complex, which allows to pass to a singular limit and reduce the original problem with a closed 1-form to a traditional problem with a Morse function.…

1999-03-23abs ↗pdf ↗

Let MM be a closed oriented manifold of dimension nn and ωω a closed 1-form on it. We discuss the question whether there exists a Riemannian metric for which ωω is co-closed. For closed 1-forms with nondegenerate zeros the question was answered completely by Calabi in 1969. The goal of this paper is to give an answ…

2007-06-15abs ↗pdf ↗

The paper classifies topological properties of specific geometric forms on manifolds.

problem Classifying topological properties of closed G~2\widetilde{\mathrm{G}}_2, SL(3;C)\mathrm{SL}(3;\mathbb{C}) and SL(3;R)2\mathrm{SL}(3;\mathbb{R})^2 forms.
method Algebraic and topological techniques, including characteristic classes and obstruction theory, with recent hh-principles.
result Complete classification of closed SL(3;C)\mathrm{SL}(3;\mathbb{C}) forms up to homotopy.

In this note we construct a first example of a closed 3-form of G~2\tilde G_2-type on S3×S4S^3\times S^4. We prove that S3×S4S^3\times S^4 does not admit a homogeneous 3-form of G~2\tilde G_2-type. Thus our example is a first example of a closed 3-form of G~2\tilde G_2-type on a compact 7-manifold which is not stably homogeneou…

2006-03-08abs ↗pdf ↗

New findings on hypersurfaces with specific curvature properties in space forms.

problem Characterizing hypersurfaces with almost constant curvature in space forms.
method Analyzing starshaped hypersurfaces with various curvature conditions.
result Closed starshaped hypersurfaces with almost constant mean curvature or higher order mean curvature are close to geodesic spheres.

Survey on closed-form Fisher-Rao distance expressions.

problem Finding closed-form expressions for Fisher-Rao distance.
method Collect and present examples of closed-form expressions for Fisher-Rao distance of discrete and continuous distributions.
result Presentation of closed-form expressions for Fisher-Rao distance of various distributions.

Study magnetic fields on special Lie groups, proving non-existence of certain types.

problem Existence of closed 2-forms with specific properties on non-singular 2-step nilpotent Lie groups.
method Analyzing left-invariant magnetic fields on 2-step nilpotent Lie groups, proving non-existence and existence results.
result Strong obstruction and non-existence of closed 2-forms of type II on non-singular Lie algebras.

This paper extends Lusternik-Schnirelmann category to non-compact manifolds.

problem Extending Lusternik-Schnirelmann category to non-compact manifolds.
method Explanation and extension of Farber's results to non-compact manifolds.
result Farber's results hold equally well on non-compact manifolds, and new phenomena occur in gradient flows.

Symplectic capacities of domains near balls are well-defined, but not for all C1C^1-close domains.

problem Understanding symplectic capacities of domains near balls and their stability.
method General theorem about contact forms close to Zoll ones, spectral invariants for contact forms.
result Existence of minimizing geodesics in the space of contact forms.

Study shows finiteness of magnetic hypersurfaces on closed manifolds.

problem Understanding the finiteness of magnetic hypersurfaces on closed manifolds.
method Introduced a dynamical version of the second fundamental form to generalize a previous result.
result Real-analytic negatively ss-curved magnetic systems on closed real-analytic manifolds have only finitely many closed totally ss-magnetic hypersurfaces.

Solves embedding problem for 5D manifolds into Calabi-Yau 3-folds.

problem Embedding a 5D manifold into a Calabi-Yau 3-fold with a specific 3-form.
method Defines 'strongly pseudoconvex' 3-forms and shows solvability of embedding problem for these forms under certain conditions.
result Perturbative embedding problem can be solved for closed strongly pseudoconvex 3-forms if a vector space of obstructions vanishes.

We use the one parameter fixed point theory of Geoghegan and Nicas to get information about the closed orbit structure of transverse gradient flows of closed 1-forms on a closed manifold M. We define a noncommutative zeta function in an object related to the first Hochschild homology group of the Novikov ring associate…

2001-04-25abs ↗pdf ↗

We apply a local systolic-diastolic inequality for contact forms and odd-symplectic forms on three-manifolds to bound the magnetic length of closed curves with prescribed geodesic curvature (also known as magnetic geodesics) on an oriented closed surface. Our results hold when the prescribed curvature is either close t…

2019-02-04abs ↗pdf ↗

Layer-wise networks have a closed-form solution and a stopping criterion.

problem Training networks one layer at a time without backpropagation.
method Proved the closed-form solution using the kernel Mean Embedding and Neural Indicator Kernel.
result Layer-wise networks have a closed-form solution and a stopping criterion.

We study the relation between JJ-anti-invariant 22-forms and pseudoholomorphic curves in this paper. We show the zero set of a closed JJ-anti-invariant 22-form on an almost complex 44-manifold supports a JJ-holomorphic subvariety in the canonical class. This confirms a conjecture of Draghici-Li-Zhang. A higher di…

2018-08-28abs ↗pdf ↗

The systolic ratio of a contact form on a closed three-manifold is the quotient of the square of the shortest period of closed Reeb orbits by the contact volume. We show that every co-orientable contact structure on any closed three-manifold is defined by a contact form with arbitrarily large systolic ratio. This shows…

2017-09-05abs ↗pdf ↗

Improved portfolio optimization using VaR and CVaR with NMVM models.

problem Optimizing portfolios with VaR and CVaR under NMVM distributions.
method Transformed mean-CVaR-skewness problems into quadratic optimization with closed-form solutions for NMVM models.
result Approximate closed-form expressions for VaR and CVaR of NMVM portfolios.

The paper explores spaces of Kähler and symplectic forms on 4-manifolds.

problem Investigating the properties of Kähler and symplectic forms on 4-manifolds.
method Analyzing the uniqueness, connectedness, and openness of spaces of Kähler forms and introducing holomorphically tamed symplectic forms.
result Formulated a parallel question for holomorphically tamed symplectic forms and related it to Kähler-type symplectic forms.