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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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48 results for Janardan Galton Watson process

This paper models stock prices using a Janardan Galton Watson process.

problem Modeling stock price fluctuations and predicting market trends.
method Extends Janardan Galton Watson process to model stock prices, considering initial close price and number of offspring.
result The model predicts return values and probability of market extinction.

The paper explores statistical limits for detecting correlation in tree structures.

problem Detecting correlation between two tree structures.
method Investigates conditions for existence of one-sided tests in the limit of large tree depth.
result Identifies a phase transition at correlation parameter s=αs = \sqrt{α}, where tests exist for s>αs > \sqrt{α}.

We compute exact values respectively bounds of "distances" - in the sense of (transforms of) power divergences and relative entropy - between two discrete-time Galton-Watson branching processes with immigration GWI for which the offspring as well as the immigration is arbitrarily Poisson-distributed (leading to arbitra…

2010-05-20abs ↗pdf ↗

Random hyperbolic surfaces with punctures converge to the Brownian sphere.

problem Understanding the geometry of random hyperbolic surfaces with punctures.
method Rescaling and encoding via plane trees with continuous labels.
result Rescaled random hyperbolic surfaces converge to the Brownian sphere.

The purpose of this paper is to design an algorithm for the computation of the counterparty risk which is competitive in regards of a brute force "Monte-Carlo of Monte-Carlo" method (with nested simulations). This is achieved using marked branching diffusions describing a Galton-Watson random tree. Such an algorithm le…

2012-03-11abs ↗pdf ↗

Ensemble learning is a statistical paradigm built on the premise that many weak learners can perform exceptionally well when deployed collectively. The BART method of Chipman et al. (2010) is a prominent example of Bayesian ensemble learning, where each learner is a tree. Due to its impressive performance, BART has rec…

2018-10-01abs ↗pdf ↗

A study on the depth of graph neural networks on sparse graphs, revealing a dichotomy based on the Kesten-Stigum ratio.

problem Determining the optimal depth of graph neural networks for sparse graphs.
method Analyzing the sparse contextual stochastic block model with a message-passing classifier.
result The value of depth is governed by the Kesten-Stigum ratio, with thresholds dividing performance into geometric and branching processes.

Several probabilistic models from high-dimensional statistics and machine learning reveal an intriguing --and yet poorly understood-- dichotomy. Either simple local algorithms succeed in estimating the object of interest, or even sophisticated semi-definite programming (SDP) relaxations fail. In order to explore this p…

2016-10-17abs ↗pdf ↗

This note provides an error bound for the Hartman-Watson integral's leading term.

problem Bounding the error of the leading term of the Hartman-Watson integral.
method Asymptotic expansion analysis focusing on the regime rt=ρrt=ρ constant.
result The error term is bounded uniformly as ϑ(t,ρ)170t|\vartheta(t,ρ)|\leq \frac{1}{70}t.

A new method TNW-CATE estimates treatment effects using neural networks.

problem Estimating heterogeneous treatment effects with limited controls and many treatments.
method Trainable Nadaraya-Watson regression with shared parameters neural network.
result TNW-CATE outperforms traditional methods in various simulation experiments.

Paper provides an upper bound for bias of Nadaraya-Watson kernel regression.

problem Estimating bias of Nadaraya-Watson kernel regression for finite bandwidths.
method Proposes an upper bound for bias under Lipschitz assumptions, extending to discontinuous derivatives and multidimensional domains.
result Upper bound on bias for finite bandwidths, tighter than previous infinitesimal bandwidth analysis.

We show that any exceptional non-trivial Dehn surgery on a twist knot, except the trefoil, yields a 3-manifold whose fundamental group is left-orderable. This is a generalization of a result of Clay, Lidman and Watson, and also gives a new supporting evidence for a conjecture of Boyer, Gordon and Watson.

2011-09-14abs ↗pdf ↗

We study the secondary structure of RNA determined by Watson-Crick pairing without pseudo-knots using Milnor invariants of links. We focus on the first non-trivial invariant, which we call the Heisenberg invariant. The Heisenberg invariant, which is an integer, can be interpreted in terms of the Heisenberg group as wel…

2008-09-18abs ↗pdf ↗

Authors derive the first two terms of the Hartman-Watson distribution's expansion for small t.

problem The Hartman-Watson distribution's integral density is difficult to evaluate numerically for small t.
method Saddle point methods and numerical estimates of the integrand.
result Obtained the first two terms of the to0t o 0 expansion of the Hartman-Watson distribution.

We prove that the link of a complex normal surface singularity is an L--space if and only if the singularity is rational. This via a recent result of Hanselman, J. Rasmussen, S. D. Rasmussen and Watson (proving the conjecture of Boyer, Gordon and Watson), shows that a singularity link is not rational if and only if its…

2015-10-24abs ↗pdf ↗

Paper develops NW kernel estimator for LSPs with Wasserstein bounds.

problem Capturing nuanced dynamics in time series data with evolving statistical characteristics.
method Nadaraya-Watson kernel smoothing for conditional probability estimation, using Wasserstein and sliced Wasserstein distances.
result Established convergence rates and bounds for NW-based conditional probability estimator in LSPs.

Boyer, Gordon, and Watson have conjectured that an irreducible rational homology 3-sphere is an L-space if and only if its fundamental group is not left-orderable. Since large classes of L-spaces can be produced from Dehn surgery on knots in the 3-sphere, it is natural to ask what conditions on the knot group are suffi…

2014-10-07abs ↗pdf ↗

A new loss function for VAEs improves image quality and efficiency.

problem Training VAEs to generate realistic images requires a loss function that reflects human perception.
method Based on Watson's perceptual model, the loss function computes a weighted distance in frequency space, accounts for luminance and contrast masking, and is extended to color images.
result VAEs trained with the new loss function generated high-quality, less blurry images with fewer artifacts and less computational resources.

It has been recently conjectured by Boyer-Gordon-Watson that a closed, orientable, irreducible 33-manifold MM is a Heegaard Floer LL-space if and only if π1(M)π_1(M) is not left-orderable. In this article, we study this conjecture from the point of view of lattice cohomology, an invariant introduced by Némethi which is…

2013-08-08abs ↗pdf ↗

Estimates time-series drifts from i.i.d. data using a direct Nadaraya-Watson plug-in method.

problem Nonparametric estimation of Schrödinger bridge drifts from single time interval data.
method Direct Nadaraya-Watson plug-in estimator based on kernelized numerator and denominator terms.
result Uniform non-asymptotic bound, CLT under undersmoothing, and adaptive bandwidth selector.

Boyer, Gordon, and Watson have conjectured that an irreducible rational homology 3-sphere is an L-space if and only if its fundamental group is not left-orderable. Since Dehn surgeries on knots in S3S^3 can produce large families of L-spaces, it is natural to examine the conjecture on these 3-manifolds. Greene, Lewalle…

2017-11-30abs ↗pdf ↗

The paper introduces a method to quantify uncertainty in neural networks without parametric assumptions.

problem Uncertainty quantification for neural network predictions.
method Nonparametric estimation of conditional label distribution using Nadaraya-Watson kernel.
result The method effectively disentangles aleatoric and epistemic uncertainties.

Let L \subset S^3 denote an alternating link and Sigma(L) its branched double-cover. We give a short proof of the fact that the fundamental group of Sigma(L) admits a left-ordering iff L is an unlink. This result is originally due to Boyer-Gordon-Watson.

2011-07-26abs ↗pdf ↗

A new polynomial invariant for strongly involutive links.

problem Characterizing strongly involutive links using polynomial invariants.
method Introducing a two-variable polynomial invariant \(P^e\) with equivariant skein relations.
result Specialisation of \(P^e\) recovers the graded Euler characteristic of a spectral sequence.

Generative models use kernel smoothing for conditioning on small example sets.

problem Improving generative models' performance with limited conditioning examples.
method Showed that cross-attention conditioning is equivalent to kernel smoothing, specifically a Nadaraya--Watson kernel smoother.
result The approach predicts and confirms three failure regimes for kernel-based conditioning.

Study on predicting graph labels at nodes using local averaging and distance estimation.

problem Predicting graph labels at nodes given observations at other nodes.
method Local averaging and distance estimation methods for graph regression.
result Alternative methods can achieve standard nonparametric rates even when graph neighborhoods are too large or small.

We provide an efficient algorithm for the classical problem, going back to Galton, Pearson, and Fisher, of estimating, with arbitrary accuracy the parameters of a multivariate normal distribution from truncated samples. Truncated samples from a dd-variate normal N(μ,Σ){\cal N}(\mathbfμ,\mathbfΣ) means a samples is only re…

2018-09-11abs ↗pdf ↗

TAP transfers knowledge from unlabeled data to improve cross-modal learning.

problem Improving supervised learning performance using unlabeled data from a different modality.
method Probabilistic approach for missing information estimation, kernel regression, cross-attention module, TAP neural network.
result TAP significantly improves generalization across different domains and neural network architectures.

This study improves estimation of locally stationary functional time series using NW method.

problem Accurately capturing time-dependence in locally stationary functional time series with time-varying covariates.
method Nadaraya-Watson (NW) estimation procedure for the conditional distribution of LSFTS.
result Established convergence rates of NW estimator for LSFTS with respect to Wasserstein distance.

We show that the resulting manifold by rr-surgery on a large class of two-bridge knots has left-orderable fundamental group if the slope rr satisfies certain conditions. This result gives a supporting evidence to a conjecture of Boyer, Gordon and Watson that relates LL-spaces and the left-orderability of their funda…

2013-01-12abs ↗pdf ↗

New theory shows how multi-head attention reduces variance and decorrelates outputs.

problem Understanding and optimizing multi-head attention in neural networks.
method Developed a statistical theory linking multi-head attention to ensemble Nadaraya-Watson estimators.
result MHA variance reduction depends on head decorrelation, not just head count.

We show that the fundamental group of the double branched cover of an infinite family of homologically thin, non-quasi-alternating knots is not left-orderable, giving further support for a conjecture of Boyer, Gordon, and Watson that an irreducible rational homology 3-sphere is an L-space if and only if its fundamental…

2013-10-07abs ↗pdf ↗

This paper addresses the statistical properties of time series driven by rational bubbles a la Blanchard and Watson (1982), corresponding to multiplicative maps, whose study has recently be revived recently in physics as a mechanism of intermittent dynamics generating power law distributions. Using insights on the beha…

1999-10-08abs ↗pdf ↗

Transformers can approximate Kalman Filtering in linear systems with small error.

problem Approximating Kalman Filtering using Transformers for linear dynamical systems.
method Two-step reduction: 1) Softmax self-attention block approximates Nadaraya-Watson kernel smoothing, 2) This estimator approximates Kalman Filter.
result Constructs a Transformer that implements the Kalman Filter with small additive error, uniformly bounded in time.

Motivated by Clay and Watson's question on left-orderability of the fundamental group of the resultant space of an rr'-surgery on the (p,q)(p, q)-cable knots for r(pqpq,pq)r' \in (pq-p-q,pq), this paper proves by elementary means that for specific pairs of (p,q)(p,q)-cable knots of torus knots, r[pq1,pq]r' \in [pq-1,pq] gives a surgery yi…

2016-10-04abs ↗pdf ↗