Research
On-device research index

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.

169,051 papers · 148 categories

Trend · papers per month

25.0%50.0%75.0%100.0% · Jun 199319922001200920172026
48 results for Riemannian optical geometry

The paper solves the isoperimetric problem in Riemannian optical geometry, proving circles minimize lengths with area constraints.

problem Optical geometry of static spherically symmetric spacetimes.
method Applying isoperimetric problem results to curves in Riemannian optical geometry.
result Length-minimizing curves with area constraints are circles, with implications for photon spheres.

Model explains optical illusions using geometric sub-Riemannian geodesics.

problem Understanding and explaining geometrical optical illusions.
method Neuro-mathematical model based on sub-Riemannian geodesics in the Roto-Translation Group.
result Illusory contours are described as geodesics in a new metric.

Study of optical geometries with intrinsic torsion in general relativity.

problem Understanding null line distributions and their properties in Lorentzian manifolds.
method Investigation of intrinsic torsion and congruences of null curves, extending to generalized optical geometries.
result Characterization of conformal properties of null line distributions and congruences.

Trajectories of light rays in a static spacetime are described by unparametrised geodesics of the Riemannian optical metric associated with the Lorentzian spacetime metric. We investigate the uniqueness of this structure and demonstrate that two different observers, moving relative to one another, who both see the univ…

2011-01-23abs ↗pdf ↗

The objective of this article is to build up a general theory of geometrical optics for spinning light rays in an inhomogeneous and anisotropic medium modeled on a Finsler manifold. The prerequisites of local Finsler geometry are reviewed together with the main properties of the Cartan connection used in this work. The…

2007-07-02abs ↗pdf ↗

We explore a natural generalization of systolic geometry to Finsler metrics and optical hypersurfaces with special emphasis on its relation to the Mahler conjecture and the geometry of numbers. In particular, we show that if an optical hypersurface of contact type in the cotangent bundle of the 2-dimensional torus encl…

2013-08-26abs ↗pdf ↗

We pursue a geometrical approach to gravitational lensing theory. We present a survey of the background theory of General Relativity, including particular properties of the Schwarzschild and Kerr solutions. Next we outline a proof of the Gauss Bonnet theorem and its applications to surfaces in optical geometry, as deve…

2011-11-21abs ↗pdf ↗

Recent work by Jaffe and Scardicchio has expressed the optical approximation to the Casimir effect as a sum over geometric quantities. The first two authors have developed a technique which uses the complex geometry of the space of oriented affine lines in R3{\Bbb{R}}^3 to describe reflection of rays off a surface. Thi…

2004-06-21abs ↗pdf ↗

Sturm theory applied to symplectic geometry and mechanics.

problem Detecting geometric properties of solutions in symplectic geometry and mechanics.
method Generalization of symplectic Sturm theory to Hamiltonians and application to semi-Riemannian manifolds and singular Lagrangian systems.
result Detection of conjugate and focal points on semi-Riemannian manifolds and geometrical properties of solutions space.

We consider the problem of density estimation on Riemannian manifolds. Density estimation on manifolds has many applications in fluid-mechanics, optics and plasma physics and it appears often when dealing with angular variables (such as used in protein folding, robot limbs, gene-expression) and in general directional s…

2016-11-07abs ↗pdf ↗

Optimizes parameter reconstruction for optical scatterometry using Gaussian process regression.

problem Efficiently reconstructing geometry parameters of micro/nanostructures from scatterometry measurements.
method Bayesian optimization with Gaussian-process regression to find optimal parameter values.
result Gaussian process regression accelerates the optimization process for numerical simulations.

We study the geometric properties of holomorphic distributions of totally null mm-planes on a (2m+ε)(2m+ε)-dimensional complex Riemannian manifold (M,g)(\mathcal{M}, \bm{g}), where ε0,1ε\in {0,1} and m2m \geq 2. In particular, given such a distribution N\mathcal{N}, say, we obtain algebraic conditions on the Weyl tensor and t…

2011-07-12abs ↗pdf ↗

Study on almost Robinson geometries, focusing on their intrinsic torsion and leaf space properties.

problem Investigating the geometry of almost Robinson manifolds, a Lorentzian analog of almost Hermitian manifolds.
method Classification based on intrinsic torsion, analysis of leaf space properties, and conformal invariants.
result Comprehensive classification of almost Robinson manifolds based on their intrinsic torsion.

We prove that a potential qq can be reconstructed from the Dirichlet-to-Neumann map for the Schrodinger operator Δg+q-Δ_g + q in a fixed admissible 3-dimensional Riemannian manifold (M,g)(M,g). We also show that an admissible metric gg in a fixed conformal class can be constructed from the Dirichlet-to-Neumann map for $Δ_…

2010-11-02abs ↗pdf ↗

We recover phase from intensity measurements using optics-based random projections.

problem Recovering phase from intensity measurements with unknown transmission matrix.
method Our method leverages conjugation of rows in the unknown matrix and interference with reference signals to cast the problem as a Euclidean distance geometry.
result We accurately recover the missing phase and mitigate quantization and sensitivity effects.

We consider a triality between the Zermelo navigation problem, the geodesic flow on a Finslerian geometry of Randers type, and spacetimes in one dimension higher admitting a timelike conformal Killing vector field. From the latter viewpoint, the data of the Zermelo problem are encoded in a (conformally) Painleve-Gullst…

2008-11-18abs ↗pdf ↗

Classifies Ricci flat Lorentzian manifolds with Kerr-like optical structures.

problem Classifying Ricci flat Lorentzian manifolds with specific optical structures.
method Simple construction method to explicitly create examples of Ricci flat Lorentzian manifolds.
result Two large classes of 4-dimensional Kerr type manifolds, each fibering over open Riemann surfaces.

Multi-layer optical film has been found to afford important applications in optical communication, optical absorbers, optical filters, etc. Different algorithms of multi-layer optical film design has been developed, as simplex method, colony algorithm, genetic algorithm. These algorithms rapidly promote the design and …

2018-12-07abs ↗pdf ↗

Paper tackles depth estimation and optic disc-cup segmentation from color fundus images.

problem Depth estimation and optic disc-cup segmentation from color fundus images.
method Uses fully convolutional networks for monocular retinal depth estimation and optic disc-cup segmentation.
result Demonstrates improved accuracy in depth estimation and optic disc-cup segmentation.

Optical flow refers to the visual motion observed between two consecutive images. Since the degree of freedom is typically much larger than the constraints imposed by the image observations, the straightforward formulation of optical flow as an inverse problem is ill-posed. Standard approaches to determine optical flow…

2016-11-04abs ↗pdf ↗

GANPOP uses deep learning to estimate optical properties from single images, improving accuracy over existing methods.

problem Estimating optical properties from single wide-field images.
method Conditional generative adversarial networks trained on paired images and optical property maps.
result GANPOP estimates optical properties with 58% higher accuracy than single-snapshot optical property technique in human gastrointestinal specimens.

Paper develops a deforestation detection system using optical and SAR data.

problem Detecting tree-loss in dense forests using satellite data.
method Combines optical and SAR data, uses KL expansion for anomaly detection, and Hidden Markov Model for classification.
result Hybrid method achieves high accuracy and robustness in sparse optical data.

We consider the anisotropic Calderon problem of recovering a conductivity matrix or a Riemannian metric from electrical boundary measurements in three and higher dimensions. In the earlier work \cite{DKSaU}, it was shown that a metric in a fixed conformal class is uniquely determined by boundary measurements under two …

2013-05-06abs ↗pdf ↗

Express Wavenet reduces neural network parameters to 1% of standard networks.

problem Optical neural networks with high parameter count.
method Wavelet modulation, random shift wavelets, expressway structure.
result Express Wavenet achieves high accuracy with significantly fewer parameters.

New ML models improve VVLC channel characterization for vehicular OWC.

problem Inaccurate channel models for VVLC due to mobility effects.
method Machine learning (ML) models incorporating ambient light, turbulence, and reflection effects.
result ML models predict VVLC channel loss and CFR more accurately than existing methods.

Designs chiral photonic structures using machine learning for efficient optical properties.

problem Optimizing chiral photonic nanostructures for light-matter interactions.
method Evolutionary algorithm and neural network approach for rapid optimization.
result Frequency-dependent modification in reflected light's degree of circular polarization.

New methods for constructing null fluid metrics and solving optical lift conjectures.

problem Constructing null fluid metrics and solving optical lift conjectures.
method Explicit parameterization of null fluid metrics under Kerr type optical structures.
result New explicit metrics, including Kerr black holes and Ricci flat examples.

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 ↗

Paper proposes a graph model for optimal AP deployment in indoor optical wireless networks.

problem Challenges in deploying optical wireless networks due to LoS requirement and limited range.
method Graph modeling approach to identify minimum number of APs and their optimal locations.
result Optimal deployment of APs ensures connectivity and minimizes interference in indoor environments.

Improved object segmentation and tracking in video using optical flow and initial state conditioning.

problem Challenges in fully unsupervised object-centric learning from video data.
method Weakly-supervised approach using optical flow and initial state conditioning.
result Conditioning the model on simple object location cues significantly improves instance segmentation in realistic synthetic data.