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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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265177102 · Jun 202019922001200920172026
48 results for symmetric bilinear tensor

Generalizes Riemann's results on flat coordinates for non-symmetric bilinear forms.

problem Finding flat coordinates for non-symmetric bilinear forms.
method Provides explicit necessary and sufficient conditions for a tensor field of type (0,2) to be flat.
result Explicit conditions for a tensor field to have constant entries in local coordinates.

It is shown how one can apply the classification of the holonomy algebras of Lorentzian manifolds to solve some problems. In particular, a new proof to the classification of Lorentzian manifolds with recurrent curvature tensor is given; the classification of two-symmetric Lorentzian manifolds is explained; conformally …

2010-11-30abs ↗pdf ↗

We study the structure group of a canonical algebraic curvature tensor built from a symmetric bilinear form, and show that in most cases it coincides with the isometry group of the symmetric form from which it is built. Our main result is that the structure group of the direct sum of such canonical algebraic curvature …

2011-08-10abs ↗pdf ↗

The theory of harmonic symmetric bilinear forms on a Riemannian manifold is an analogue of the theory of harmonic exterior differential forms on this manifold. To show this, we must consider every symmetric bilinear form on a Riemannian manifold as a one-form with values in the cotangent bundle of this manifold. In thi…

2019-08-06abs ↗pdf ↗

The paper explores geometric decompositions for Ricci tensors and their applications.

problem Understanding Ricci tensors on compact Riemannian manifolds.
method Utilizes Berger-Ebin and York L2L^2-orthogonal decompositions.
result New insights into Ricci almost solitons and harmonic maps.

Bilinear MLPs offer a new way to interpret deep learning models without complex nonlinearities.

problem Lack of mechanistic understanding in how MLPs compute.
method Introduced bilinear MLPs without element-wise nonlinearities, analyzed their weights using tensor and eigendecomposition.
result Bilinear MLPs provide interpretable weight structures and enable adversarial attacks and overfitting analysis.

The space of tensors of metric curvature type on a Euclidean vector space carries a two-parameter family of orthogonally invariant commutative nonassociative multiplications invariant with respect to the symmetric bilinear form determined by the metric. For a particular choice of parameters these algebras recover the p…

2019-01-13abs ↗pdf ↗

We are interested in approximation of a multivariate function f(x1,,xd)f(x_1,\dots,x_d) by linear combinations of products u1(x1)ud(xd)u^1(x_1)\cdots u^d(x_d) of univariate functions ui(xi)u^i(x_i), i=1,,di=1,\dots,d. In the case d=2d=2 it is a classical problem of bilinear approximation. In the case of approximation in the L2L_2 space the bili…

2014-09-04abs ↗pdf ↗

We generalize a theorem of Bismut-Zhang, which extends the Cheeger-Mueller theorem on Ray-Singer torsion and Reidemeister torsion, to the case where the flat vector bundle over a closed manifold carries a nondegenerate symmetric bilinear form. As a consequence, we prove the Burghelea-Haller conjecture which gives an an…

2006-10-19abs ↗pdf ↗

Paper reduces sample complexity for bilinear systems identification to nearly constant.

problem Identifying discrete-time bilinear systems under bounded disturbances.
method Uses trajectory-dependent regressors and polynomial mean-square state growth analysis.
result Proves sample complexity of O~(1/ε)\widetilde{\mathcal O}(1/ε) for estimation error εε.

The classical Cartan's structural equations show in a compact way the relation between a connection and its curvature, and reveals their geometric interpretation in terms of moving frames. In order to study the mathematical properties of singularities, we need to study the geometry of manifolds endowed on the tangent b…

2011-11-02abs ↗pdf ↗

Fine-grained action segmentation in long untrimmed videos is an important task for many applications such as surveillance, robotics, and human-computer interaction. To understand subtle and precise actions within a long time period, second-order information (e.g. feature covariance) or higher is reported to be effectiv…

2019-06-03abs ↗pdf ↗

Let VV be a finite dimensional vector space over a field FF of characteristic different from 2, and let QQ be a nondegenerate, symmetric, bilinear form on VV. Let C(V,Q)C\ell(V,Q) be the Clifford algebra determined by VV and QQ. The bilinear form QQ extends in a natural way to a nondegenerate, symmetric, bilinear fo…

2017-01-25abs ↗pdf ↗

Consider a smooth manifold with a smooth metric which changes bilinear type from Riemann to Lorentz on a hypersurface ΣΣ with radical tangent to ΣΣ. Two natural bilinear symmetric forms appear there, and we use it to analyze the geometry of ΣΣ. We show the way in which these forms control the smooth extensibility ov…

2003-06-10abs ↗pdf ↗

New connections found for quaternionic and para-quaternionic structures.

problem Characterizing integrability of generalized quaternionic and para-quaternionic structures.
method Defined and characterized integrability with respect to a abla abla-bracket on the generalized tangent bundle.
result Existence of a canonical connection for these structures.

New mathematical proposal for TQFTs using TMF-modules.

problem Constructing new types of TQFTs at the intersection of topology, algebra, physics, and homotopy theory.
method Defines TMF-modules associated with symmetric bilinear forms and assigns them to closed 3-manifolds and maps of TMF-modules to 4-dimensional cobordisms.
result Invariants of 4-manifolds arising from 6-dimensional superconformal field theories, conjecturally generalizing the theta function of a lattice.

Defines metrics and Einstein tensors on Riemannian manifolds, proving vanishing for non-commutative two-torus.

problem Defining metrics and Einstein tensors on Riemannian manifolds.
method Defines bilinear functionals of vector fields and differential forms, generalizing to non-commutative geometry.
result Proves the vanishing of the Einstein functional for the conformally rescaled geometry of the noncommutative two-torus.

The paper studies quarter-symmetric connections on Hermitian and Kähler manifolds.

problem Examining quarter-symmetric connections on almost Hermitian and Kähler manifolds.
method Analyzing the curvature tensors and their properties with respect to quarter-symmetric connections.
result Constructed tensors that do not depend on the quarter-symmetric connection generator, including the Weyl projective curvature tensor.

Study biderivations in complete Leibniz algebras, extending Lie algebra results.

problem Defining and studying biderivations in complete Leibniz algebras.
method Analyze biderivations according to two definitions, provide conditions for biderivations, and compare symmetric and skew-symmetric biderivations.
result Necessary and sufficient conditions for biderivations in Leibniz algebras are provided.

In this note we prove the following three algebraic facts which have applications in the theory of holonomy groups and homogeneous spaces: Any irreducibly acting connected subgroup $G \subset Gl(n,\rr)$ is closed. Moreover, if GG admits an invariant bilinear form of Lorentzian signature, GG is maximal, i.e. it is con…

2005-07-04abs ↗pdf ↗

Sprays on Frechet manifolds connect connections and tangent structures.

problem Characterizing linear symmetric connections on Frechet manifolds.
method Constructing connection maps and linear symmetric connections on tangent and second-order tangent bundles using sprays.
result A bijective correspondence exists between linear symmetric connections on tangent bundles and sprays.

Defines metric bundles for manifold geometries, unifying various types of metrics.

problem Unified framework for various types of metrics on manifolds.
method Formalizes metric bundles and defines open fiberwise cones for nondegenerate symmetric bilinear forms.
result Unified framework subsumes Riemannian and pseudo-Riemannian metrics, and extends to other structures.

The paper studies T-tensor of spherically symmetric Finsler metrics and characterizes metrics satisfying the T-condition.

problem Characterizing spherically symmetric Finsler metrics with vanishing T-tensor.
method Deriving a general expression for the T-tensor and characterizing metrics satisfying the T-condition.
result Characterization of spherically symmetric Finsler metrics with vanishing T-tensor.

Systematic prolongation for Killing two-tensors in symmetric spaces.

problem Understanding Killing two-tensors in symmetric spaces.
method Systematic prolongation procedure for Killing two-tensors, focusing on locally symmetric spaces.
result Natural quadratic mapping from Killing fields to Killing two-tensors on irreducible locally symmetric spaces of compact type.

New neural networks respect symmetries in symmetric tensors, improving efficiency and generalization.

problem Learning from symmetric tensors efficiently and respecting their inherent symmetries.
method Developed two characterizations of linear permutation equivariant functions between symmetric power spaces of R^n.
result These functions are highly data efficient compared to standard MLPs and generalize well to different sizes of symmetric tensors.

Defines semi-symmetric metric connection on super warped products.

problem Computing curvature and Ricci tensors on super warped products.
method Introduced semi-symmetric metric connection and conditions for Einstein spaces.
result Conditions for super warped product spaces to be Einstein with semi-symmetric metric connection.

The paper studies para-Sasaki-like manifolds with a new metric connection.

problem Investigating new geometric structures on para-Sasaki-like manifolds.
method Deriving relations between connections, analyzing curvature tensors, studying solitons, constructing examples.
result Derived relations and properties of para-Sasaki-like manifolds with the generalized symmetric metric connection.

The paper studies a new connection on Riemannian manifolds and finds conditions for symplectic manifolds.

problem Exploring a new quarter-symmetric non-metric connection on Riemannian manifolds.
method Analyzes the properties and relations of the torsion tensor and curvature tensors of the new connection.
result Conditions for a manifold to be symplectic when endowed with the new connection.

The paper classifies Killing tensor fields on Riemannian symmetric spaces.

problem Understanding Killing tensor fields on Riemannian symmetric spaces.
method Reduced study to compact irreducible spaces, introduced top slot Killing tensor fields, and classified quadratic fields.
result Quadratic Killing tensor fields on Riemannian symmetric spaces of rank one are spanned by top-slot and decomposable fields.

We study left-invariant symmetric Killing 2-tensors on 2-step nilpotent Lie groups endowed with a left-invariant Riemannian metric, and construct genuine examples, which are not linear combinations of parallel tensors and symmetric products of Killing vector fields.

2018-11-22abs ↗pdf ↗

Paper studies second order symmetric parallel tensors in generalized f.pk-space forms.

problem Exploring properties of second order symmetric parallel tensors in generalized f.pk-space forms.
method Analyzes the properties of second order symmetric parallel tensors and deduces the existence or non-existence of certain tensors and hypersurfaces.
result There does not exist second order skew-symmetric parallel tensor in f.pk-space form. There is no parallel hypersurface in a generalized f.pk-space form but there is semi-parallel hypersurface.

Characterizes Lorentzian manifolds with semi-symmetric metric connections.

problem Characterizing Lorentzian manifolds with specific metric connections.
method Analyzing semi-symmetric metric connections with vanishing curvature and recurrent torsion.
result Establishes conditions for perfect fluid and generalized Robertson-Walker spacetimes.

Via a non degenerate symmetric bilinear form we identify the coadjoint representation with a new representation and so we induce on the orbits a simplectic form. By considering Hamiltonian systems on the orbits we study some features of them and finally find commuting functions under the corresponding Lie-Poisson brack…

2003-01-28abs ↗pdf ↗