activity
20152026
most citedThe Universal Approximation Property

74 citations · 120 across the 41 of their papers we have counts for

collaborators

46 papers

cs.LG2026

Certifiably Interpretable Training of ReLU-MLPs for Boolean Tasks with Guaranteed Truth-Table Generalization

Hrad Ghoukasian, Anastasis Kratsios

As compute scales, models evolve, and training algorithms advance, our ability to explain the increasingly powerful AI systems they enable is eroding. To help safeguard interpretab…

stat.ML2026

A Closed-Form Formula for Consistent Lipschitz Regression on Metric Spaces with Sparse Neural Network Realizations

Ruiyang Hong, Hrad Ghoukasian, Anastasis Kratsios

Several classical machine-learning methods, such as KRRs and SVRs, are both computationally and analytically tractable since their estimators either admit closed-form expressions o…

math.PR2026

NeuralChaos: Optimal Adapted Approximation of Square Integrable Predictable Processes

Anastasis Kratsios, Giulia Livieri, Philipp Schmocker

We address fundamental challenges in representing and computing -valued predictable square-integrable processes over , collected in the space $\mathcal{H}^2_…

cs.LG2026

Algorithmic Foundations of Deep Learning: Complexity-Theoretic Rates and a Characterization of Universal Approximation

Anastasis Kratsios, Simone Brugiapaglia, Bum Jun Kim +2

Feedforward neural network (NN) expressivity is typically studied by emulating optimal basis-expansion schemes. While powerful, this perspective is incomplete: it primarily capture…

q-fin.CP2026

PIVOT: Bridging Black-Scholes Implied-Volatility and Price Objectives via Differentiable Jäckel Operator

Raeid Saqur, Yannick Limmer, Anastasis Kratsios +2

Modern option-learning systems operate in two coordinates: price space, where markets quote and no-arbitrage constraints are most naturally enforced, and implied volatility (IV) sp…

math.FA2026

Structure-Preserving Reconstruction of Convex Lipschitz Functionals on Hilbert Spaces from Finite Samples

Anastasis Kratsios

Convex functionals are ubiquitous in applied analysis, appearing as value functions, risk measures, super-hedging prices, and loss functionals in machine learning. In many applicat…

cs.LG2026

MEMOA: Massive Mixtures of Online Agents via Mean-Field Decentralized Nash Equilibria

Xuwei Yang, David B. Emerson, Fatemeh Tavakoli +1

In the modern age of large-scale AI, federated learning has become an increasingly important tool for training large populations of AI agents; however, its computational and commun…

cs.LG2026

Adaptivity Under Realizability Constraints: Comparing In-Context and Agentic Learning

Anastasis Kratsios, A. Martina Neuman, Philipp Petersen

We compare in-context learning with fixed queries and agentic learning with adaptive queries for uniform approximation of task families. We consider two settings: an unrestricted r…

cs.LG2026

Neural Operators Can Discover Functional Clusters

Yicen Li, Jose Antonio Lara Benitez, Ruiyang Hong +3

Operator learning is reshaping scientific computing by amortizing inference across infinite families of problems. While neural operators (NOs) are increasingly well understood for…

cs.CC2026

Certifiable Boolean Reasoning Is Universal

Wenhao Li, Anastasis Kratsios, Hrad Ghoukasian +1

The proliferation of agentic systems has thrust the reasoning capabilities of AI into the forefront of contemporary machine learning. While it is known that there \emph{exist} neur…

stat.ML2026

Statistical Guarantees for Reasoning Probes on Looped Boolean Circuits

Anastasis Kratsios, Giulia Livieri, A. Martina Neuman

We study the statistical behavior of reasoning probes in a stylized model of iterative computation inspired by neural algorithmic reasoning. The underlying computation is given by…

cs.LG2025

One model to solve them all: 2BSDE families via neural operators

Takashi Furuya, Anastasis Kratsios, Dylan Possamaï +1

We introduce a mild generative variant of the classical neural operator model, which leverages Kolmogorov--Arnold networks to solve infinite families of second-order backward stoch…

cs.LG2025

Autonomous-Flow-Based Generation

Hossein Rouhvarzi, Anastasis Kratsios

We show that using autonomous-flow-based generation, one can universally approximate orientation-preserving diffeomorphisms defined on the cube by Neural ODEs with rate $\mathcal{O…

cs.LG2025

Quantifying The Limits of AI Reasoning: Systematic Neural Network Representations of Algorithms

Anastasis Kratsios, Dennis Zvigelsky, Bradd Hart

A main open question in contemporary AI research is quantifying the forms of reasoning neural networks can perform when perfectly trained. This paper answers this by interpreting r…

stat.ML2025

Learning from one graph: transductive learning guarantees via the geometry of small random worlds

Nils Detering, Luca Galimberti, Anastasis Kratsios +2

Since their introduction by Kipf and Welling in , a primary use of graph convolutional networks is transductive node classification, where missing labels are inferred within…

cs.LG2025

Neural Operators Which Certifiably Simultaneously Solve Infinitely Many Convex Programs using Logarithmic Rank and Linear Complexity

Anastasis Kratsios, Ariel Neufeld, Philipp Schmocker

Neural operators (NOs) are a class of deep learning models designed to simultaneously solve infinitely many related problems by casting them into an infinite-dimensional space, whe…

cs.LG2025

LoRA Fine-Tuning Without GPUs: A CPU-Efficient Meta-Generation Framework for LLMs

Reza Arabpour, Haitz Sáez de Ocáriz Borde, Anastasis Kratsios

Low-Rank Adapters (LoRAs) have transformed the fine-tuning of Large Language Models (LLMs) by enabling parameter-efficient updates. However, their widespread adoption remains limit…

q-fin.MF2025

Generative Market Equilibrium Models with Stable Adversarial Learning via Reinforcement

Anastasis Kratsios, Xiaofei Shi, Qiang Sun +1

We present a general computational framework for solving continuous-time financial market equilibria under minimal modeling assumptions while incorporating realistic financial fric…

cs.LG2025

Approximation Rates in Besov Norms and Sample-Complexity of Kolmogorov-Arnold Networks with Residual Connections

Anastasis Kratsios, Bum Jun Kim, Takashi Furuya

Inspired by the Kolmogorov-Arnold superposition theorem, Kolmogorov-Arnold Networks (KANs) have recently emerged as an improved backbone for most deep learning frameworks, promisin…

stat.ML2025

Is In-Context Universality Enough? MLPs are Also Universal In-Context

Anastasis Kratsios, Takashi Furuya

The success of transformers is often linked to their ability to perform in-context learning. Recent work shows that transformers are universal in context, capable of approximating…

cs.CV2025

Keep It Light! Simplifying Image Clustering Via Text-Free Adapters

Yicen Li, Haitz Sáez de Ocáriz Borde, Anastasis Kratsios +1

In the era of pre-trained models, effective classification can often be achieved using simple linear probing or lightweight readout layers. In contrast, many competitive clustering…

stat.ML2025

Step by Step: Adaptive Gradient Descent for Training L-Lipschitz Neural Networks

Kyle Sung, Kholood Khalil, Noah Forman +2

We demonstrate that applying an eventual decay to the learning rate (LR) in empirical risk minimization (ERM), where the mean-squared-error loss is minimized using standard gradien…

math.OC2024

Polynomial Scaling is Possible For Neural Operator Approximations of Structured Families of BSDEs

Takashi Furuya, Anastasis Kratsios

Neural operator (NO) architectures learn nonlinear maps between infinite-dimensional function spaces and are widely used to accelerate simulation and enable data-driven model disco…

cs.LG2024

Inverse Entropic Optimal Transport Solves Semi-supervised Learning via Data Likelihood Maximization

Mikhail Persiianov, Arip Asadulaev, Nikita Andreev +5

Learning conditional distributions is a central problem in machine learning, which is typically approached via supervised methods with paired data .…