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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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4386129172 · Jun 202019922001200920172026
48 results for finite-time transition density

We start by showing that the finite-time absolute ruin probability in the classical risk model with constant interest force can be expressed in terms of the transition probability of a positive Ornstein-Uhlenbeck type process, say X. Our methodology applies to the case when the dynamics of the aggregate claims process …

2010-06-11abs ↗pdf ↗

New method calibrates stochastic reduced-order models from data efficiently.

problem Challenges in estimating drift and diffusion coefficients from data for high-dimensional systems.
method Uses a novel relationship between conditional score and transition density to constrain model coefficients directly from finite-lag statistics.
result Validated on various systems, the method reproduces statistical and dynamical properties of the original models.

Proposes a method for approximating transition densities of SDEs driven by gamma processes.

problem Calculating transition densities for SDEs driven by gamma processes.
method Taylor-type approximation and conditional expectation of multiple stochastic integrals.
result Efficiency of the proposed method demonstrated through numerical tests.

MAFLA improves sampling from heavy-tailed distributions using MH-inspired corrections.

problem Sampling from heavy-tailed and multimodal distributions when neither target nor proposal densities can be evaluated.
method Metropolis-Adjusted Fractional Langevin Algorithm (MAFLA) with Score Balance Matching.
result MAFLA significantly improves finite-time sampling accuracy over unadjusted fractional Langevin dynamics.

FourNet approximates financial transition densities using Fourier transforms.

problem Approximating transition densities in finance with high accuracy.
method FourNet is a novel FFNN with Gaussian activation, learning from characteristic functions.
result FourNet can approximate transition densities arbitrarily well with finite neurons.

New gauge fields modify Fokker-Planck dynamics without changing the stationary state.

problem Understanding and modifying nonreversible dynamics in Fokker-Planck models.
method Formulate nonreversible perturbations as gauge fields, mapping to supersymmetric Hamiltonians, and learning finite forces.
result Learned finite forces can recover the optimal Lyapunov-equation solution in nonconvex landscapes.

We introduce closed-form transition density expansions for multivariate affine jump-diffusion processes. The expansions rely on a general approximation theory which we develop in weighted Hilbert spaces for random variables which possess all polynomial moments. We establish parametric conditions which guarantee existen…

2011-04-28abs ↗pdf ↗

We present a plausible micro-founded model for the previously postulated power law finite time singular form of the crash hazard rate in the Johansen-Ledoit-Sornette model of rational expectation bubbles. The model is based on a percolation picture of the network of traders and the concept that clusters of connected tr…

2016-01-28abs ↗pdf ↗

New findings confirm parallels to De Giorgi's conjecture for phase transitions in higher dimensions.

problem Understanding phase transitions with bounded index in higher-dimensional spaces.
method Establishing parallels to De Giorgi's conjecture for general solutions of bounded Morse index.
result Finite index solutions to the Allen--Cahn equation in R4\mathbb{R}^4 are one-dimensional, and this holds for all 4n74 \leq n \leq 7.

Persistent entropy detects phase transitions in complex systems.

problem Detecting phase transitions in complex systems.
method Established a general theorem for persistent entropy to reliably detect phase transitions, introduced operational framework for finite-time computations.
result Persistent entropy exhibits an asymptotically non-vanishing gap across phases, robust numerical signatures across experiments.

New models for short rates show longer periods at higher rates.

problem Modeling longer periods of higher interest rates.
method Developed a class of time-homogeneous one-factor Markov diffusion models with specific boundary conditions.
result Explicit expressions for bond prices and transition densities in new probability measure.

We consider a defaultable asset whose risk-neutral pricing dynamics are described by an exponential Levy-type martingale subject to default. This class of models allows for local volatility, local default intensity, and a locally dependent Levy measure. Generalizing and extending the novel adjoint expansion technique o…

2013-12-27abs ↗pdf ↗

The paper tackles joint learning of linear systems, improving accuracy with pooled data.

problem Estimating transition matrices of multiple related linear systems more accurately.
method Developed novel techniques to bound estimation errors and establish high probability bounds for singular values.
result Significant gains in accuracy achieved by pooling data across systems.

We show that a surface group contained in a reductive real algebraic group can be deformed to become Zariski dense, unless its Zariski closure acts transitively on a Hermitian symmetric space of tube type. This is a kind of converse to a rigidity result of Burger, Iozzi and Wienhard.

2010-09-12abs ↗pdf ↗

The paper introduces new estimators for multivariate functions using Fourier methods.

problem Estimating multivariate functions like densities and regression functions.
method Monte Carlo estimators based on the Fourier integral theorem.
result Established rates of convergence for new estimators, often superior to existing methods.

Detect changes in noisy dynamical systems using empirical approximations and finite-sample bounds.

problem Change detection in noisy dynamical systems
method Partition-based empirical approximations and finite-state stationary distribution stability
result Finite-sample bound for empirical stationary density

Fold maps associated to geodesic random walks on curved spaces.

problem Understanding the behavior of geodesic random walks on curved surfaces.
method Analyzing mappings from the unit tangent sphere to a manifold with non-positive curvature.
result For odd powers of the unit tangent sphere, these mappings are fold maps.

Study phase transitions in noisy transformer dynamics on spheres.

problem Understanding phase transitions in noisy transformer dynamics on spheres.
method Sharp Beckner--Onofri/logarithmic HLS inequality, Funk--Hecke/Bessel coefficients, degree-two quartic obstruction.
result Sharp global-minimizer dichotomy and phase transitions in noisy transformer dynamics in arbitrary dimension.

New study shows low-degree polynomial algorithms struggle at clause densities close to Fix's.

problem Finding satisfying assignments in random k-SAT formulas at high clause densities.
method Analysis of low-degree polynomial algorithms and a new many-way overlap gap property.
result No efficient algorithms can find satisfying assignments at clause densities close to Fix's.

Paper proposes a new approach to optimal transport for vector and matrix densities.

problem Optimal transport for vector and matrix densities with positivity and action transitivity constraints.
method Gauge-theoretic approach using semi-direct product groups of diffeomorphisms and gauge transformations.
result Bures-type metrics on semi-direct product groups relate to Wasserstein-type metrics on vector and matrix densities via Riemannian submersions.

Graph diffusion processes approximate manifold heat semigroups using graph transition matrices.

problem Approximating manifold heat semigroups from graph data under low regularity conditions.
method Iterating graph transition matrix PP to approximate Qt=etΔQ_t = e^{tΔ}, bounding error in \infty-norm.
result Convergence rates O(N2/(d+6))O(N^{-2/(d+6)}) for manifold heat semigroup approximation, valid for in-sample and out-of-sample.

We study an extension of the classic stochastic multi-armed bandit problem which involves multiple plays and Markovian rewards in the rested bandits setting. In order to tackle this problem we consider an adaptive allocation rule which at each stage combines the information from the sample means of all the arms, with t…

2020-01-30abs ↗pdf ↗

Representations based on random walks can exploit discrete data distributions for clustering and classification. We extend such representations from discrete to continuous distributions. Transition probabilities are now calculated using a diffusion equation with a diffusion coefficient that inversely depends on the dat…

2012-10-19abs ↗pdf ↗

We study optimal estimation for sparse principal component analysis when the number of non-zero elements is small but on the same order as the dimension of the data. We employ approximate message passing (AMP) algorithm and its state evolution to analyze what is the information theoretically minimal mean-squared error …

2015-03-01abs ↗pdf ↗

This article is devoted to the maximisation of HARA utilities of L{é}vy switching process on finite time interval via dual method. We give the description of all f-divergence minimal martingale measures in initially enlarged filtration, the expression of their Radon-Nikodym densities involving Hellinger and Kulback-Lei…

2018-07-24abs ↗pdf ↗

This work explores efficient reinforcement learning with density features in low-rank MDPs.

problem Efficient reinforcement learning with density features in low-rank MDPs.
method Proposes algorithms for off-policy estimation and online construction of exploratory data distributions.
result Demonstrates sample-efficient learning with density features in low-rank MDPs, overcoming technical challenges.

The Sinkhorn-Knopp algorithm converges quickly but the number of iterations is poorly understood.

problem Understanding the number of iterations required for the Sinkhorn-Knopp algorithm to converge.
method Analyzing the Sinkhorn-Knopp algorithm for matrices with a specific density threshold.
result The Sinkhorn-Knopp algorithm requires Ω(n1/2/ε)Ω(n^{1/2}/\varepsilon) iterations for matrices with density γ<1/2γ<1/2.

We study the phase transition of dynamical herd behaviors for the yen-dollar exchange rate in the Japanese financial market. It is obtained that the probability distribution of returns satisfies the power-law behavior with three different values of the scaling exponent 3.11 (one time lag ττ = 1 minute), 2.81 (30 minut…

2004-08-28abs ↗pdf ↗

Study learns linear system dynamics from noisy bilinear data.

problem Learning linear dynamics from bilinear observations with process and measurement noise.
method Regression with Kronecker product design, data-dependent and independent error bounds.
result Upper bounds on statistical error rates and sample complexity for learning dynamics matrices.

Machine learning predicts critical points for directed percolation models.

problem Determining critical points for directed percolation models.
method Supervised and unsupervised machine learning algorithms (CNN and DBSCAN) were used.
result Machine learning accurately predicts critical points for both models.

This paper gives a brief overview on the nonparametric techniques that are useful for financial econometric problems. The problems include estimation and inferences of instantaneous returns and volatility functions of time-homogeneous and time-dependent diffusion processes, and estimation of transition densities and st…

2004-11-01abs ↗pdf ↗

Generative Stochastic Networks (GSNs) have been recently introduced as an alternative to traditional probabilistic modeling: instead of parametrizing the data distribution directly, one parametrizes a transition operator for a Markov chain whose stationary distribution is an estimator of the data generating distributio…

2013-12-19abs ↗pdf ↗

We reprove a result concerning certain ruin in the classical problem of the probability of ruin with risky investments and several of it's generalisations. We also provide the combined transition density of the risk and investment processes in the diffusion case.

2005-06-08abs ↗pdf ↗