Genre
Optimal Spatio-Temporal Decoupling for Bayesian Conformal Prediction
Online Conformal Prediction (CP) struggles to balance temporal adaptability and structural stability. Feedback-driven methods (e.g., Adaptive Conformal Inference (ACI)) suffer from systemic marginal under-coverage and high interval variance during abrupt shifts, while temporally discounted Bayesian CP suffers from severe structural lag and uncalibrated interval bloat. We propose State-Adaptive Bayesian Conformal Prediction (SA-BCP) to achieve optimal spatio-temporal decoupling. By gating long-term temporal inertia with spatial kernel-density evidence, SA-BCP proactively expands intervals for recognized historical regimes while maintaining tight efficiency during stable states. We rigorously prove this mechanism's optimality, identifying a minimax bias-variance tradeoff governed by an evidence threshold $K$. Extensive benchmarks on volatile financial datasets (2016--2026), including AMD, Gold, and GBP/USD, demonstrate that SA-BCP consistently minimizes the strictly proper Winkler score across diverse confidence levels. Specifically, SA-BCP resolves the systematic under-coverage inherent to ACI variants while simultaneously reducing the uncalibrated interval bloat of Bayesian CP by 10\% to 37\% under high-confidence requests. By elegantly navigating this tradeoff, SA-BCP achieves an optimal balance between conditional reliability and predictive efficiency.
Concentration and Calibration in Predictive Bayesian Inference
Predictive Bayesian inference (PBI) represents a model-and prior-agnostic approach to standard Bayesian inference which allows users to quantify uncertainty for a functional of interest only by specifying a forward predictive model for future unobserved data. The flexibility and generality of this framework have led to a host of novel algorithms for implementing this approach, and many empirical applications, yet the reliability of the resulting inferences for the underlying statistical functional of interest remains unclear. Herein, we demonstrate that when using PBI for a population functional of interest, the resulting posterior concentrates onto a well-defined quantity that explicitly depends on the forward predictive model used to implement the predictive recursion underlying the method. Furthermore, the forward predictive model entirely determines the uncertainty quantification produced in PBI. Consequently, our results show that if the predictive model does not capture all relevant features of the data, and, even in very simple examples, the coverage of predictive Bayes credible sets for the population value of the functional of interest can be arbitrarily close to zero. We carefully explain why this occurs, and show that this behavior is directly tied to the inaccuracy of the forward predictive model used to produce future observations within the PBI framework. As a consequence, our results imply that in order for PBI to deliver calibrated posterior inferences, the resulting predictive engine used to generate posterior samples must contain, in a well-defined sense, the true DGP, else inferences generated under this framework will not be calibrated.
Batch Normalization for Neural Networks on Complex Domains
Nguyen, Xuan Son, Grozavu, Nistor
Riemannian neural networks have proven effective in solving a variety of machine learning tasks. The key to their success lies in the development of principled Riemannian analogs of fundamental building blocks in deep neural networks (DNNs). Among those, Riemannian batch normalization (BN) layers have shown to enhance training stability and improve accuracy. In this paper, we propose BN layers for neural networks on complex domains. The proposed layers have close connections with existing Riemannian BN layers. We derive essential components for practical implementations of BN layers on some complex domains which are less studied in previous works, e.g., the Siegel disk domain. We conduct experiments on radar clutter classification, node classification, and action recognition demonstrating the efficacy of our method.
Gradient Regularized Newton Boosting Trees with Global Convergence
Zozoulenko, Nikita, Falkowski, Daniel, Cass, Thomas, Gonon, Lukas
Gradient Boosting Decision Trees (GBDTs) dominate tabular machine learning, with modern implementations like XGBoost, LightGBM, and CatBoost being based on Newton boosting: a second-order descent step in the space of decision trees. Despite its empirical success, the global convergence of Newton boosting is poorly understood compared to first-order boosting. In this paper, we introduce Restricted Newton Descent, which studies convex optimization with Newton's method on Hilbert spaces with inexact iterates, based on the concepts of cosine angle and weak gradient edge. Within this framework, we recover Newton boosting with GBDTs and classical finite-dimensional theory as special cases. We first prove that vanilla Newton boosting achieves a linear rate of convergence for smooth, strongly convex losses that satisfy a Hessian-dominance condition. To handle general convex losses with Lipschitz Hessians, we extend a recent gradient regularized Newton scheme to the restricted weak learner setting. This scheme minimally modifies the classical algorithm by introducing an adaptive $\ell_2$-regularization term proportional to the square root of the gradient norm at each iteration. We establish a $\mathcal{O}(\frac{1}{k^2})$ rate for this scheme, thereby obtaining a globally convergent second-order GBDT algorithm with a rate matching that of first-order boosting with Nesterov momentum. In numerical experiments, we show that our scheme converges while vanilla Newton boosting may diverge.
Decentralized Proximal Stochastic Gradient Langevin Dynamics
Islam, Mohammad Rafiqul, Zhu, Lingjiong
Decentralized learning is a learning process in which data is distributed across computational agents or collected by individual agents, and model parameters are computed as the consensus of the agents. It has gained a lot of interest for applications where agents can collaboratively learn a predictive model without sharing their own data, but sharing only their local models with their immediate neighbors to generate a global model [He et al., 2018, Hendrikx et al., 2019, Arjevani et al., 2020]. We assume there are N agents who are connected over an undirected communication network G = (V,E) where V = {1,...,N} represents the agents and E V V denotes the set of edges; i.e., if agent i and j are connected then (i,j) E implies (j,i) E. Suppose we have a collection of n independent and identically distributed (i.i.d.) data pairs zi = (ai,yi), where ai Rp is the feature vector and yi the label or response of the i-th observation. Let Z = [z1,z2,,zn] Rnp be sampled from the distribution p(Z|x) where the parameter x Rd has a common prior. The goal is to sample from the posterior distribution p(x|Z) p(Z|x)p(x) by distributing Z among N agents such that Zi = {zi1,zi2,,zini} is the subset of data exclusive to agent i.
Randomized Subspace Nesterov Accelerated Gradient
Omiya, Gaku, Poirion, Pierre-Louis, Takeda, Akiko
Randomized-subspace methods reduce the cost of first-order optimization by using only low-dimensional projected-gradient information, a feature that is attractive in forward-mode automatic differentiation and communication-limited settings. While Nesterov acceleration is well understood for full-gradient and coordinate-based methods, obtaining accelerated methods for general subspace sketches that use only projected-gradient information and can improve over full-dimensional Nesterov acceleration in oracle complexity is technically nontrivial. We develop randomized-subspace Nesterov accelerated gradient methods for smooth convex and smooth strongly convex optimization under matrix smoothness and generic sketch moment assumptions. The key technical ingredient is a three-sequence formulation tailored to matrix smoothness, which recovers the corresponding classical Nesterov methods in the full-dimensional case. The resulting theory establishes accelerated oracle-complexity guarantees and makes explicit how matrix smoothness and the sketch distribution enter the complexity. It also provides a unified basis for comparing sketch families and identifying when randomized-subspace acceleration improves over full-dimensional Nesterov acceleration in oracle complexity.
Recursive Maximum Likelihood Estimation for Interacting Particle Systems using Virtual Particles
Sharrock, Louis, Kantas, Nikolas, Pavliotis, Grigorios A.
We study recursive maximum likelihood estimation for stochastic interacting particle systems based on continuous observation of a single particle. In this regime, consistent estimation of the finite-particle log-likelihood is not possible, even in the limit as the number of particles $N\rightarrow\infty$ and the time horizon $t\rightarrow\infty$. We thus seek to optimise the stationary log-likelihood of the limiting mean-field system. We achieve this via a form of stochastic gradient estimate in continuous time, with stochastic gradient estimates computed using the continuous trajectory of the single observed particle, alongside a virtual interacting particle system and a virtual tangent interacting particle system, which are integrated with the online parameter estimate. For fixed numbers of real and virtual particles, we show that the resulting algorithms drive the gradient of a finite-particle surrogate objective to zero as $t\to\infty$. We then prove that, in the iterated limit $t\to\infty$ followed by $N,M\to\infty$, these surrogate gradients converge uniformly to the gradient of the stationary log-likelihood of the limiting mean-field system, yielding convergence to its stationary points. We illustrate the method on several numerical examples, including a model with quadratic confinement and interaction potentials, a model of interacting FitzHugh--Nagumo neurons, and a stochastic Kuramoto model.
Cole Allen's journey from young athlete and Caltech grad to accused gunman in D.C. attack
Things to Do in L.A. Tap to enable a layout that focuses on the article. Cole Allen's journey from young athlete and Caltech grad to accused gunman in D.C. attack Cole Tomas Allen selfie before the attack in Washington, D.C., according to a pretrial detention memo filed by prosecutors Wednesday. This is read by an automated voice. Please report any issues or inconsistencies here . A quiet, respected tutor and engineer from Southern California with a "godly" upbringing allegedly attempted to assassinate President Trump at the White House correspondents' dinner, shocking those who knew him. Allen's social media accounts under the handle "coldForce" show years of posts criticizing Trump and supporting Ukraine, but contain no indication of violent intent despite the alleged assassination plot.
You're drinking prosecco wrong! Scientists reveal why you should never opt for a flute
Trump reveals'absolutely pathetic' first words he says Bill Maher uttered at fabled White House visit Charles had late-stage ALS and couldn't speak or move. Bigamist pastor's'marriage scam': Five-times-wed author told women God wanted them to be together for twisted ulterior motive, wives say The rat'apocalypse' forcing residents in a northwestern state to catch vermin with their bare hands Kylie Jenner's BFF Stassie reveals dramatic butt reduction in skimpy bikini after cosmetic surgery'regrets' I had agonising acid reflux every day - but then overnight it stopped thanks to something you can buy in any supermarket. With 39 bedrooms, 59 bathrooms and its own X-ray machine, America's most expensive home hits the market for $400million - but will anyone afford to buy it? 'Dog Whisperer' Cesar Millan reveals price of the world's'safest' collar - and it TALKS to your pet Moment'disgruntled former employee' smashed car full of explosives into Portland athletics club caught on camera'She's spiralling badly': How Meghan and Harry have burned ALL their bridges as insiders reveal spectacular fallout with Anna Wintour and Kardashians, money woes - and'problems' that are worse than anyone realises Former FBI deputy director Dan Bongino'living in fear' as he issues astonishing warning after mysteriously leaving intel agency Whether it's a celebration or a bottomless brunch, nothing hits the spot quite like a glass of fizz. But it turns out you've probably been drinking prosecco wrong this entire time.
Health experts call for AI addiction to be classed as a mental illness - as sufferers report feeling suicidal when separated from their favourite chatbot
'They're going to come for me': Ex-FBI deputy director reveals he's'living in fear' as he issues astonishing warning House Republican makes shock claim about Trump assassination attempt being'an inside job' Truth about'budget Ozempic' supplement that'eradicates hunger': Where to get it, precisely how to take it, how fast you'll lose weight... and embarrassing side effects to know Family of woman abducted as a newborn describe fresh tragedy involving her'twin' brother... as kidnap victim reveals she is pregnant and shocking name she plans to give baby Horror in Portland as'disgruntled former employee' crashes into athletics club in car'packed with EXPLOSIVES' 'She's spiralling badly': How Meghan and Harry have burned ALL their bridges as insiders reveal spectacular fallout with Anna Wintour and Kardashians, money woes - and'problems' that are worse than anyone realises McDonald's phases out free refills with patronizing sign as customers rage'we understand we'll eat elsewhere' I had agonising acid reflux every day - but then overnight it stopped thanks to something you can buy in any supermarket. Family suffers unimaginable second tragedy as Kansas State freshman, 19, dies in frat house fall 13 years after his sister's death I was abused by expat millionaires in a Dubai hotel and left with horrific injuries. Alleged JPMorgan sex slave scandal makes me think of my female bosses... and the shocking office nickname one brazen colleague earned: KENNEDY Moment Italian waiter shows off his football skills - only to backheel ball into wine glass that smashes in customer's face Gunfire erupts outside Chris Brown's LA mansion amid Rihanna assault legal drama What Hollywood insiders are saying about those Harry Styles sexuality rumors after shock Zoe Kravitz engagement... as friends finally address the'Larry' gossip Health experts are calling for AI chatbot addiction to be recognised as a mental illness, as the number of supposed cases climbs. On online forums, more and more teenagers and young adults are now saying they feel'addicted' to their AI companions and struggle to kick the habit. These young users spend hours every day roleplaying complex fantasies, venting their frustrations, and seeking emotional connection with digital companions.