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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.

168,694 papers · 148 categories

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82163245326 · May 202619922001200920172026
48 results for exact form

In this paper, we first define the equivariant infinitesimal ηη-form, then we compare it with the equivariant ηη-form, modulo exact forms, by a locally computable form. As a consequence, we obtain the singular behavior of the equivariant ηη-form, modulo exact forms, as a function on the acting Lie group. This result…

2018-08-13abs ↗pdf ↗

Reformulations of Donaldson's "tamed to compatible" question are obtained in terms of spaces of exact forms on a compact almost complex manifold (M2n,J)(M^{2n},J). In dimension 4, we show that JJ admits a compatible symplectic form if and only if JJ admits tamed symplectic forms with arbitrarily given JJ-anti-invariant p…

2011-11-30abs ↗pdf ↗

On a compact, oriented, Riemannian manifold, the Hodge decomposition theorem associates a smooth primitive to any exact smooth form omega. In this paper, we show that given a smooth family of exact smooth forms omega(t), the family of associated primitives is also a smooth family with respect to t.

2009-11-16abs ↗pdf ↗

For a smooth family of exact forms on a smooth manifold, an algorithm for computing a primitive family smoothly dependent on parameters is given. The algorithm is presented in the context of a diagram chasing argument in the Čech-de Rham complex. In addition, explicit formulas for such primitive family are presented.

2019-03-19abs ↗pdf ↗

Let M be a manifold, possibly with boundary. We show that the deRham differential from k-forms to exact (k+1)-forms has a continuous right inverse when both spaces are given the weak Whitney topology. This antidifferential operator is given a fairly explicit formula depending on the choice of a suitable good cover of M…

2013-11-06abs ↗pdf ↗

This paper is devoted, first of all, to give a complete unified proof of the Characterization Theorem for compact generalized pp-Kähler manifolds (Theorem 3.2). The proof is based on the classical duality between "closed" positive forms and "exact" positive currents. In the last part of the paper we approach the gener…

2017-07-11abs ↗pdf ↗

Locally-verifiable conditions ensure exactness of spline discrete de Rham complex.

problem Ensuring cohomological equivalence of spline discrete complex to continuous de Rham complex.
method Theoretical analysis and locally-verifiable sufficient conditions for exactness.
result Locally-verifiable conditions guarantee exactness of hierarchical B-spline discrete de Rham complex.

Exact selective inference with randomization for Gaussian regression models.

problem Exact selective inference in Gaussian regression models.
method Introduces a pivot for exact selective inference with randomization, reducing the problem to a bivariate truncated Gaussian distribution.
result Our pivot leads to exact inference and produces narrower confidence intervals than related methods.

The paper proves geometric rigidity using harmonic twisted spinors and scalar curvature comparison.

problem Proving geometric rigidity for closed Riemannian spin manifolds with specific properties.
method Using Gromov's exact-lift two-form method and harmonic spinors to analyze scalar curvature.
result The original metric is Einstein, and the universal cover is real hyperbolic in the positive-spectrum case.

An anologue of the Calabi invariant for Poisson manifolds is considered. For any Poisson manifold PP, the Poisson bracket on C(P)C^{\infty}(P) extends to a Lie bracket on the space Ω1(P)Ω^{1}(P) of all differential one-forms, under which the space Z1(P)Z^{1}(P) of closed one-forms and the space B1(P)B^{1}(P) of exact one-forms a…

1996-05-05abs ↗pdf ↗

In this letter, I consider the issue of pricing risky debt by following Merton's approach. I generalize Merton's results to the case where the interest rate is modeled by the CIR term structure. Exact closed forms are provided for the risky debt's price.

1998-08-16abs ↗pdf ↗

The paper revisits and analyzes the tmd-operator in almost Kähler manifolds.

problem Constructing an elliptic operator analogous to the ∂∂ operator in complex or Kähler manifolds.
method Local analysis estimates and demonstration using the Atiyah-Hitchin-Singer operator.
result Every d-exact (1,1)-form is globally tmd-exact for compact taming symplectic 4-manifolds.

We propose a method for explicit computation of the Chern character form of a holomorphic Hermitian vector bundle (E,h)(E,h) over a complex manifold XX in a local holomorphic frame. First, we use the descent equations arising in the double complex of (p,q)(p,q)-forms on XX and find explicit degree decomposition of the Cher…

2014-02-25abs ↗pdf ↗

We provide in this note two relevant examples of Lagrangian cobordisms. The first one gives an example of two exact Lagrangian submanifolds which cannot be composed in an exact fashion. The second one is an example of an exact Lagrangian cobordism on which all primitive of the Liouville form is not constant on the nega…

2013-01-29abs ↗pdf ↗

We show that every closed L_infty,loc - form on R^n is exact. Differential is understood in the sense of currents. The proof does not use any explicit geometric constructions. De Rham theorem follows.

2007-12-11abs ↗pdf ↗

We show a relationship between Chern-Simons 1- and 3-forms and harmonic forms on a principal bundle. Doing so requires one to consider an adiabatic limit. For the 3-form case, assume that G is simple and the corresponding Chern-Weil 4-form is exact. Then, the Chern-Simons 3-form on the princpal bundle G-bundle, minus a…

2008-10-25abs ↗pdf ↗

We study the relation between Sobolev inequalities for differential forms on a Riemannian manifold (M,g)(M,g) and the Lq,pL_{q,p}-cohomology of that manifold. The Lq,pL_{q,p}-cohomology of (M,g)(M,g) is defined to be the quotient of the space of closed differential forms in Lp(M)L^p(M) modulo the exact forms which are exterior diff…

2005-06-03abs ↗pdf ↗

We present a general definition of the Poisson bracket between differential forms on the extended multiphase space appearing in the geometric formulation of first order classical field theories and, more generally, on exact multisymplectic manifolds. It is well defined for a certain class of differential forms that we …

2002-02-27abs ↗pdf ↗

We use Chern-Weil theory for Hermitian holomorphic vector bundles with canonical connections for explicit computation of the Chern forms of trivial bundles with special non-diagonal Hermitian metrics. We prove that every del-dellbar exact real form of the type (k,k) on an n-dimensional complex manifold X arises as a di…

2011-02-05abs ↗pdf ↗

Exact Bayesian inference for discrete models using probability generating functions.

problem Discrete statistical models with infinite support and continuous priors.
method Probabilistic programming language with automatic differentiation and probability generating functions.
result Genfer tool provides exact solutions for a wide range of inference problems.

A new discrete calculus for bundle-valued forms is proposed and validated.

problem Discretization of exterior calculus for bundle-valued forms.
method Discretization of Cartan's exterior calculus for differential forms with values in vector bundles.
result The proposed discrete operator mimics the continuous exterior covariant derivative and ensures numerical convergence.

Let MM be a closed oriented surface and let ΩΩ be a non-exact 2-form. Suppose that the magnetic flow φφ of the pair (g,Ω)(g,Ω) is Anosov. We show that the longitudinal KAM-cocycle of φφ is a coboundary if and only the Gaussian curvature is constant and ΩΩ is a constant multiple of the area form thus extending the res…

2005-01-11abs ↗pdf ↗

We exhibit two three-parameter families of locally conformal symplectic forms on the solvmanifold Mn,kM_{n,k} considered in [1], and show, using the Hodge-de Rham theory for the Lichnerowicz cohomology that that they are not dωd_ω exact, i.e. their Lichnerowicz classes are non-trivial (Theorem 1). This has several import…

2003-08-18abs ↗pdf ↗

Exact Gaussian Processes for massive datasets using non-stationary sparsity-discovering kernels.

problem High computational and storage costs for exact GPs in large datasets.
method Develop non-stationary kernels that allow the GP to discover sparse structure naturally.
result Exact Gaussian Processes scalable to over 5 million data points.

We study the topology of exact and Stein fillings of the canonical contact structure on the unit cotangent bundle of a closed surface ΣgΣ_g, where gg is at least 2. In particular, we prove a uniqueness theorem asserting that any Stein filling must be s-cobordant rel boundary to the disk cotangent bundle of ΣgΣ_g. For …

2015-10-22abs ↗pdf ↗

Exact second-order optimization for deep learning reduces computational cost and improves performance.

problem Inadequate use of second-order optimization methods in deep learning due to high computational cost and non-convexity.
method Developed an exact stochastic second-order Newton method that addresses the non-convexity issue and provides an expression for the stochastic Hessian.
result Exact second-order Newton direction formula and its application in deep learning datasets.