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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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63127190253 · Jun 202019922001200920172026
48 results for Polarization imaging

Novel fusion network combines polarization and radiomics features for liver cancer classification.

problem Challenges in histopathological diagnosis of HCC and ICC.
method Two-tier fusion approach: feature-level and classification-level.
result Significantly enhances classification accuracy, even at reduced resolutions.

We relate the Lipschitz-Killing measures of a definable set XRnX \subset \mathbb{R}^n in an o-minimal structure to the volumes of generic polar images. For smooth submanifolds of Rn\mathbb{R}^n, such results were established by Langevin and Shifrin.Then we give infinitesimal versions of these results. As a corollary, we…

2015-12-09abs ↗pdf ↗

Study slopes of direct images in complex manifolds, proving a Mehta-Ramanathan type theorem.

problem Distribution of Harder-Narasimhan slopes in direct image sheaves.
method Analyzing asymptotic distributions of slopes under base changes of families of complex projective manifolds.
result Asymptotic distribution of slopes can be recovered from base changes over generic curves.

This paper deals with skew ruled surfaces in the Euclidean space E3\mathbb{E}^{3} which are equipped with polar normalizations, that is, relative normalizations such that the relative normal at each point of the ruled surface lies on the corresponding polar plane. We determine the invariants of a such normalized ruled …

2017-11-29abs ↗pdf ↗

The paper establishes lower bounds on Yang-Mills functionals for fibrations.

problem Analyzing the stability and nefness of direct image sheaves in fibrations.
method Generalizing mean curvature and Harder-Narasimhan filtrations to arbitrary polarized fibrations.
result Optimal lower bounds on fibered Yang-Mills functionals in terms of direct image sheaves.

The paper analyzes how multiple classifiers' disagreement and polarization affect overall accuracy.

problem Improving accuracy through ensembling multiple classifiers.
method The paper derives an upper bound for polarization, proposes a neural polarization law, and presents a tight upper bound for the error of majority vote classifiers.
result Disagreement and polarization among classifiers are linearly correlated with the target, and polarization is nearly constant for a dataset.

We study a compact invariant convex set EE in a polar representation of a compact Lie group. Polar rapresentations are given by the adjoint action of KK on p\mathfrak{p}, where KK is a maximal compact subgroup of a real semisimple Lie group GG with Lie algebra g=kp\mathfrak{g} = \mathfrak{k} \oplus \mathfrak{p}. If …

2014-11-21abs ↗pdf ↗

Neural network implementation of Brenier's polar factorization for vector fields.

problem Implementing Brenier's polar factorization theorem for vector fields using neural networks.
method Parameterizing the convex function uu as an input convex neural network and estimating the measure-preserving map MM.
result Practical neural implementation of Brenier's polar factorization theorem.

Geometrically, Kostant's Convexity Theorem is extended to submetries with a fat section.

problem Extending Kostant's Convexity Theorem to a broader class of representations.
method Introducing a new concept of 'fat section' and proving the theorem for submetries with this property.
result Kostant's Convexity Theorem is partially extended to submetries with a fat section.

In this article we are interested in the differential geometric properties of certain higher direct images of exterior powers of the sheaf of relative differentials twisted with a line bundle. We obtain explicit curvature formulas, especially in case where the said line bundle satisfies a natural curvature assumption. …

2017-04-07abs ↗pdf ↗

Polarization measurements done using Imaging Polarimeters such as the Robotic Polarimeter are very sensitive to the presence of artefacts in images. Artefacts can range from internal reflections in a telescope to satellite trails that could contaminate an area of interest in the image. With the advent of wide-field pol…

2019-11-19abs ↗pdf ↗

The paper studies obstructions to solutions of the Wess-Zumino-Witten equation and its generalizations.

problem Existence of solutions to the Wess-Zumino-Witten equation and its generalizations.
method Identification of algebraic obstructions and construction of approximate solutions using Monge-Ampère type equations.
result Approximate solutions to the generalized Wess-Zumino-Witten equation are shown to be the closest to true solutions when the latter do not exist.

Enhanced X-ray polarimetry with deep learning for better exposure times.

problem Improving sensitivity of X-ray telescopic observations with imaging polarimeters.
method A weighted maximum likelihood combination of predictions from a deep ensemble of ResNet convolutional neural networks trained on Monte Carlo event simulations.
result Improves effective exposure times by ~45% for power-law source spectra.

Despite the advantages of all-weather and all-day high-resolution imaging, SAR remote sensing images are much less viewed and used by general people because human vision is not adapted to microwave scattering phenomenon. However, expert interpreters can be trained by compare side-by-side SAR and optical images to learn…

2019-01-08abs ↗pdf ↗

We classify the polar actions on the complex hyperbolic plane up to orbit equivalence. Apart from the trivial and transitive polar actions, there are five polar actions of cohomogeneity one and four polar actions of cohomogeneity two.

2011-08-02abs ↗pdf ↗

The paper studies how Kähler polarizations degenerate to mixed polarizations on toric varieties.

problem Degeneration of Kähler polarizations to mixed polarizations on toric varieties.
method Constructing polarizations by Hamiltonian actions, finding one-parameter families of Kähler polarizations, and analyzing convergence of spaces of holomorphic sections.
result Kähler polarizations degenerate to mixed polarizations as kk increases, with specific convergence results for one-parameter families.

Polarized and GG-polarized CR manifolds are smooth manifolds endowed with a double structure: a real foliation $\Cal F$ (given by the action of a Lie group GG in the GG-polarized case) and a transverse CR distribution (E,J)(E,J). Polarized means that (E,J)(E,J) is roughly speaking invariant by $\Cal F$. Both structures ar…

2012-12-03abs ↗pdf ↗

A polarity of a projective plane is a map, often assumed to be involutive, mapping a generic point to a generic line and reciprocally. The most classical polarity is the polarity with respect to a conic, but other exist: the harmonic polarity with respect to a triangle, the polarities with respect to high-degree algebr…

2013-02-07abs ↗pdf ↗

The generic fiber of a Lagrangian fibration on an irreducible holomorphic symplectic manifold is an abelian variety. Associate a polarization type to such Lagrangian fibrations coming from polarizations on a generic fiber. We prove that this polarization type is constant in families of Lagrangian fibrations. Further, w…

2015-01-19abs ↗pdf ↗

Paper uses ResUNet-CMB to reconstruct cosmic polarization rotation from CMB data.

problem Reconstructing anisotropic cosmic polarization rotation from CMB data.
method Extended ResUNet-CMB to handle gravitational lensing and patchy reionization.
result ResUNet-CMB outperforms standard quadratic estimator in reconstructing all three effects.

The point of the paper is to show some limitations of geometrical optics in the analysis of subwavelength focusing. We analyze the resolution of the image of a line source radiating in the Maxwell fisheye and the Veselago-Pendry slab lens. The former optical medium is deduced from the stereographic projection of a virt…

2009-12-01abs ↗pdf ↗

The study introduces polarization of generalized Nijenhuis torsions and their relevance in operator fields.

problem Characterization of Haantjes C(M)C^{\infty}(M)-modules of operator fields.
method Introducing polarization of generalized Nijenhuis torsions and proving algebraic identities.
result Polarizations of generalized Nijenhuis torsions are relevant in the characterization of Haantjes C(M)C^{\infty}(M)-modules of operator fields.

Given a holomorphic family f:XSf:\mathcal{X} \to S of compact complex manifolds of dimension nn and a relatively ample line bundle LXL\to \mathcal{X}, the higher direct images RnpfΩX/Sp(L)R^{n-p}f_*Ω^p_{\mathcal{X}/S}(L) carry a natural hermitian metric. We give an explicit formula for the curvature tensor of these direct images.…

2016-11-28abs ↗pdf ↗

Assume that a projective variety together with a polarization is uniformly K-stable. If the polarization is canonical or anti-canonical, then the projective variety is uniformly K-stable with respects to any polarization sufficiently close to the original polarization.

2017-09-24abs ↗pdf ↗

Classifies totally geodesic submanifolds and polar actions on Stiefel manifolds.

problem Classifying totally geodesic submanifolds and polar actions on Stiefel manifolds.
method Classification through polar actions and cohomogeneity-one actions.
result Classification of orbits of polar actions on Stiefel manifolds.

Classifies hexagonal circular 3-webs with cubic polar curves.

problem Classifying hexagonal circular 3-webs with algebraic polar curves of degree three.
method Analyzes hexagonal circular 3-webs on unit sphere with polar points on a twisted cubic.
result Completes the classification of hexagonal circular 3-webs with algebraic polar curves of degree three.

For complex projective manifolds we introduce polar homology groups, which are holomorphic analogues of the homology groups in topology. The polar k-chains are subvarieties of complex dimension k with meromorphic forms on them, while the boundary operator is defined by taking the polar divisor and the Poincare residue …

2000-09-01abs ↗pdf ↗

We prove a criterion for an isometric action of a Lie group on a Riemannian manifold to be polar. From this criterion, it follows that an action with a fixed point is polar if and only if the slice representation at the fixed point is polar and the section is the tangent space of an embedded totally geodesic submanifol…

2010-01-20abs ↗pdf ↗

The imbalance of buying and selling functions profoundly in the formation of market trends, however, a fine-granularity investigation of the imbalance is still missing. This paper investigates a unique transaction dataset that enables us to inspect the imbalance of buying and selling on the man-times level at high freq…

2018-02-04abs ↗pdf ↗

We show that simply connected Riemannian homogeneous spaces of compact semisimple Lie groups with polar isotropy actions are symmetric, generalizing results of Fabio Podesta and the third named author. Without assuming compactness, we give a classification of Riemannian homogeneous spaces of semisimple Lie groups whose…

2018-05-09abs ↗pdf ↗

Polar manifolds are Riemannian G-manifolds admitting a "section", i.e., a complete submanifold passing through every orbit and doing so orthogonally. We consider compact simply-connected polar manifolds and achieve an equivariantly diffeomorphic classification in dimensions 5 or less. As an application, we determine wh…

2014-07-02abs ↗pdf ↗

The paper bounds abnormal and Goh-abnormal sets for metabelian Lie groups with polarizations.

problem Bounding abnormal and Goh-abnormal sets for metabelian Lie groups.
method Analyzing rank 2 polarizations and sub-Riemannian structures on metabelian Lie groups.
result Metabelian Lie groups with polarizations satisfy the minimizing Sard property.

In this paper, we generalize the polar transforms of spacelike isothermic surfaces in Q14Q^4_1 to n-dimensional pseudo-Riemannian space forms QrnQ^n_r. We show that there exist cc-polar spacelike isothermic surfaces derived from a spacelike isothermic surface in QrnQ^n_r, which are into Srn+1(c)S^{n+1}_r(c), Hr1n+1(c)H^{n+1}_{r-1}(c)

2011-11-04abs ↗pdf ↗

We give a simple sufficient condition for K-stability of polarized del Pezzo surfaces and for the existence of a constant scalar curvature Kahler metric in the Kahler class corresponding to the polarization.

2016-06-14abs ↗pdf ↗

We classify infinitesimally polar actions on compact Riemannian symmetric spaces of rank one. We also prove that every polar action on one of those spaces has the same orbits as an asystatic action.

2015-05-12abs ↗pdf ↗