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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.

168,742 papers · 148 categories

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222444666888 · Jun 202019922001200920172026
48 results for big complex local systems

Proves conjecture on deformation invariance of big fundamental groups.

problem Stability of big fundamental groups under small deformations.
method Deformation regularity of equivariant pluriharmonic maps and techniques from Shafarevich conjectures.
result Deformation openness of big fundamental groups for varieties with big complex local systems.

Uniform volume estimate for Kähler metrics in big cohomology classes.

problem Estimating volume for singular Kähler metrics in big cohomology classes.
method Generalized mixed energy estimate for functions in complex Sobolev space to big cohomology classes.
result Uniform non-collapsing volume estimate for local Kähler metrics.

Study proves stability of big bang singularity in complex system.

problem Stability of Kasner solutions in Einstein-Maxwell-scalar field-Vlasov system.
method Detailed mathematical structures and new delicate arguments.
result Nonlinear stability with Kasner exponents in full strong sub-critical regime.

Estimates Kaehler metrics' diameter in big cohomology classes.

problem Estimating the diameter of Kaehler metrics in big cohomology classes.
method Proves uniform diameter estimates using integrability conditions and stability properties of complex Monge-Ampere equations.
result Uniform diameter estimates for Kaehler metrics in big cohomology classes.

Explosive growth in data and availability of cheap computing resources have sparked increasing interest in Big learning, an emerging subfield that studies scalable machine learning algorithms, systems, and applications with Big Data. Bayesian methods represent one important class of statistic methods for machine learni…

2014-11-24abs ↗pdf ↗

Study foundational aspects of degenerate para-CR structures and their PDE systems.

problem Understanding invariants and degeneracies of submanifolds in para-CR structures.
method Analyzing split-diffeomorphisms and Levi forms, setting up foundational material.
result Equivalence of PDE system properties under 2-nondegeneracy conditions.

Paper optimizes a big data and ML risk monitoring system for financial markets.

problem Traditional risk monitoring methods are inadequate for modern financial markets due to data complexity and volume.
method Four-layer architecture integrating big data and advanced ML algorithms (LSTM, RF, GB).
result Significantly enhances efficiency and accuracy in risk management, especially in market crash risk detection.

New algorithm learns halfspaces with adversarial noise efficiently.

problem Learning halfspaces in the presence of adversarial noise.
method Polynomial-time Perceptron-like online active learning algorithm.
result Near-optimal label and sample complexity with isotropic log-concave marginal distribution.

New insights into spectral statistics of sample covariance matrix for stable linear systems.

problem Estimating high-dimensional stable state transition matrices from noisy data.
method Combining spectral theorem for non-Hermitian operators, concentration of measure, and perturbation theory.
result The spectral radius of the sample covariance matrix exhibits phase transitions in high dimensions.

Localized big bang singularities found without background solutions.

problem Proving localized big bang formation without proximity to background solutions.
method Introducing a new foliation by spacelike hypersurfaces and a time function to synchronize and stabilize the singularity.
result Maximally globally hyperbolic developments have local quiescent big bang singularities with curvature blow-up.

We consider model-free reinforcement learning for infinite-horizon discounted Markov Decision Processes (MDPs) with a continuous state space and unknown transition kernel, when only a single sample path under an arbitrary policy of the system is available. We consider the Nearest Neighbor Q-Learning (NNQL) algorithm to…

2018-02-12abs ↗pdf ↗

New methods prove controllability of non-linear systems, extending classical results.

problem Controllability of non-linear control systems.
method Analytic control system, graph completions, flows of vector fields, pseudogroup of local diffeomorphisms.
result Sufficient conditions for local controllability and accessibility of non-linear systems.

FS&P uses birth-death process to ensure global convergence of stochastic conic particle gradient descent.

problem Global optimization of non-convex objective functions over measure space.
method Introduces Fast Spawn\&Prune (FS\&P) combining CPGD with birth-death process.
result First theoretical guarantee of global convergence for discrete-time stochastic algorithms.

We study the local equivalence problem for real-analytic (Cω\mathcal{C}^ω) hypersurfaces M5C3M^5 \subset \mathbb{C}^3 which, in coordinates (z1,z2,w)C3(z_1, z_2, w) \in \mathbb{C}^3 with w=u+ivw = u+i\, v, are rigid: \[ u \,=\, F\big(z_1,z_2,\overline{z}_1,\overline{z}_2\big), \] with FF independent of vv. Specifically, we study th…

2019-04-04abs ↗pdf ↗

The study finds conditions for a third rank Killing tensor field on a 2D Riemannian torus.

problem Conditions for the existence of a third rank Killing tensor field on a 2D Riemannian torus.
method Analyzes the metric of the torus and uses Fourier coefficients to derive conditions for the function λ.
result Equations relating Fourier coefficients of the function λ determine the existence of a third rank Killing tensor field.

The rise of Big Data has led to new demands for Machine Learning (ML) systems to learn complex models with millions to billions of parameters, that promise adequate capacity to digest massive datasets and offer powerful predictive analytics thereupon. In order to run ML algorithms at such scales, on a distributed clust…

2015-12-31abs ↗pdf ↗

GT-SARAH optimizes decentralized non-convex problems with recursive variance reduction.

problem Decentralized non-convex optimization of NN functions over a network.
method Stochastic first-order gradient method with SARAH variance reduction and gradient tracking.
result Achieves εε-accurate first-order stationary point with improved gradient complexity.

A method to select important experts for Gaussian processes to balance computational efficiency and uncertainty quantification.

problem Balancing computational efficiency and uncertainty quantification in Gaussian processes for big data.
method Using graphical models to select important experts and aggregate their predictions while ensuring uncertainty quantification.
result Substantially reduces computational cost of aggregating dependent experts while ensuring calibrated uncertainty quantification.

Let G/HG/H be a contractible homogeneous Sasaki manifold. A compact locally homogeneous aspherical Sasaki manifold Γ\G/HΓ\big\backslash G/H is by definition a quotient of G/HG/H by a discrete uniform subgroup ΓGΓ\leq G. We show that a compact locally homogeneous aspherical Sasaki manifold is always quasi-regular, that is, $…

2019-06-12abs ↗pdf ↗

Improved algorithm reduces stochastic gradient complexity for large-scale learning problems.

problem High stochastic gradient complexity for large-scale learning problems.
method Hybrid Stochastic-Deterministic Minibatch Proximal Gradient (HSDMPG) algorithm.
result Achieves nearly optimal generalization in less than a single pass over data.

In this survey, we remind some fibrations structure theorems (also called Milnor's fibrations) recently proved in the real and complex case, in the local and global settings. We give several Poincaré-Hopf type formulae which relates the Euler-Poincaré characteristic of these fibers (also called Milnor's fibers) and ind…

2014-09-17abs ↗pdf ↗

New method improves likelihood-free parameter estimation in complex models.

problem Estimating parameters in simulation-based models with unknown likelihood.
method Nested multi-time-scale stochastic approximation (NMTS) method.
result Eliminates bias and accelerates convergence in likelihood-free inference.

Let (M,gTM)\big(M,g^{TM}\big) be a noncompact complete spin Riemannian manifold of even dimension nn, with kTMk^{TM} denote the associated scalar curvature. Let f ⁣:MSn(1)f\colon M\rightarrow S^{n}(1) be a smooth area decreasing map, which is locally constant near infinity and of nonzero degree. We show that if kTMn(n1)k^{TM}\geq n(n-1)

2019-12-08abs ↗pdf ↗

The paper tackles machine unlearning by designing efficient algorithms for adaptive query classes.

problem Designing efficient unlearning algorithms for machine learning models.
method Formalizes the problem and gives efficient unlearning algorithms for linear and prefix-sum query classes.
result Improved guarantees for stochastic convex optimization with reduced unlearning query complexity.

The paper studies positivity properties of cotangent bundles in complex hyperbolic manifolds with cusps.

problem Positivity properties of cotangent bundles in complex hyperbolic manifolds with cusps.
method Analyzes intrinsic positivity properties of cotangent bundles using toroidal compactifications and ample line bundles.
result The cotangent bundle is ample modulo the boundary divisor for sufficiently small rational numbers.

Agent-based modeling is a powerful simulation technique to understand the collective behavior and microscopic interaction in complex financial systems. Recently, the concept for determining the key parameters of the agent-based models from empirical data instead of setting them artificially was suggested. We first revi…

2017-03-04abs ↗pdf ↗

Characterizes and analyzes the large scale geometry of big mapping class groups of surfaces.

problem Analyzing the large scale geometry of big mapping class groups of surfaces with a unique maximal end.
method Building on previous work, the paper characterizes and analyzes the large scale geometry of big mapping class groups of surfaces with a unique maximal end.
result Proves that any locally CB big mapping class group is CB generated and gives an explicit criterion for determining which big mapping class groups are CB generated.

Continuity of complex Monge-Ampère potentials on Kähler manifolds.

problem Continuity of solutions to complex Monge-Ampère equations on compact Kähler manifolds.
method Extending DiNezza-Lu's approach to big cohomology classes, proving continuity on Zariski open sets.
result Singular Kähler-Einstein metrics have continuous potentials on the ample locus outside of the non-klt part.

The world is witnessing an unprecedented growth of cyber-physical systems (CPS), which are foreseen to revolutionize our world {via} creating new services and applications in a variety of sectors such as environmental monitoring, mobile-health systems, intelligent transportation systems and so on. The {information and …

2018-10-29abs ↗pdf ↗

The following problem is addressed: A 33-manifold MM is endowed with a triple Ω=(Ω1,Ω2,Ω3)Ω= \big(Ω^1,Ω^2,Ω^3\big) of closed 22-forms. One wants to construct a coframing ω=(ω1,ω2,ω3)ω= \big(ω^1,ω^2,ω^3\big) of MM such that, first, dωi=Ωi{\rm d}ω^i = Ω^i for i=1,2,3i=1,2,3, and, second, the Riemannian metric $g=\big(ω^1\big)^2+\big(ω^2\big)^2+\…

2019-08-02abs ↗pdf ↗