ising model
Dynamic Treatment on Networks
Nar, Bengusu, Li, Jiguang, Ročková, Veronika, Toulis, Panos
In networks, effective dynamic treatment allocation requires deciding both whom to treat and also when, so as to amplify policy impact through spillovers. An early intervention at a well-connected node can trigger cascades that change which nodes are worth targeting in the next period. Existing treatment strategies under network interference are largely static while dynamic treatment frameworks typically ignore network structure altogether. We integrate these perspectives and propose Q-Ising, a three-stage pipeline that (i) estimates network adoption dynamics via a Bayesian dynamic Ising model from a single observed panel, (ii) augments treatment adoption histories with continuous posterior latent states, and (iii) learns a dynamic policy via offline reinforcement learning. The Bayesian mechanism enables uncertainty quantification over dynamic decisions, yielding posterior ensemble policies with interpretable spillover estimates. We provide a finite-sample regret upper bound that decomposes into standard offline-RL uncertainty, network abstraction error, and first stage error in Ising state estimation. We apply our method to data from Indian village microfinance networks and synthetic stochastic block models under simulated heterogeneous susceptible-infected-susceptible (SIS) dynamics and demonstrate that adaptive targeting outperforms static centrality benchmarks.
DISCS: ABenchmark for Discrete Sampling
Sampling in discrete spaces, with critical applications in simulation and opti-1 mization, has recently been boosted by significant advances in gradient-based2 approaches that exploit modern accelerators like GPUs. However, two key chal-3 lenges hinder the further research progress in discrete sampling. First, since there4 is no consensus on experimental settings, the empirical results in different research5 papers are often not comparable. Secondly, implementing samplers and target6 distributions often requires a nontrivial amount of effort in terms of calibration,7 parallelism, and evaluation. To tackle these challenges, we propose DISCS (DIS-8 Crete Sampling), a tailored package and benchmark that supports unified and9 efficient implementation and evaluations for discrete sampling in three types of10 tasks: sampling for classical graphical models, combinatorial optimization, and11 energy based generative models. Throughout the comprehensive evaluations in12 DISCS, we acquired new insights into scalability, design principles for proposal13 distributions, and lessons for adaptive sampling design.
Binary Expansion Group Intersection Network
Conditional independence is central to modern statistics, but beyond special parametric families it rarely admits an exact covariance characterization. We introduce the binary expansion group intersection network (BEGIN), a distribution-free graphical representation for multivariate binary data and bit-encoded multinomial variables. For arbitrary binary random vectors and bit representations of multinomial variables, we prove that conditional independence is equivalent to a sparse linear representation of conditional expectations, to a block factorization of the corresponding interaction covariance matrix, and to block diagonality of an associated generalized Schur complement. The resulting graph is indexed by the intersection of multiplicative groups of binary interactions, yielding an analogue of Gaussian graphical modeling beyond the Gaussian setting. This viewpoint treats data bits as atoms and local BEGIN molecules as building blocks for large Markov random fields. We also show how dyadic bit representations allow BEGIN to approximate conditional independence for general random vectors under mild regularity conditions. A key technical device is the Hadamard prism, a linear map that links interaction covariances to group structure.
Information Theoretic Properties of Markov Random Fields, and their Algorithmic Applications
Markov random fields are a popular model for high-dimensional probability distributions. Over the years, many mathematical, statistical and algorithmic problems on them have been studied. Until recently, the only known algorithms for provably learning them relied on exhaustive search, correlation decay or various incoherence assumptions. Bresler gave an algorithm for learning general Ising models on bounded degree graphs. His approach was based on a structural result about mutual information in Ising models. Here we take a more conceptual approach to proving lower bounds on the mutual information.
DISCS: A Benchmark for Discrete Sampling
Sampling in discrete spaces, with critical applications in simulation and optimization, has recently been boosted by significant advances in gradient-based approaches that exploit modern accelerators like GPUs. However, two key challenges are hindering further advancement in research on discrete sampling.