arXiv AI

TSFM Meets LLM: Context as Covariates

The paper introduces Context as Covariates (CoCo), a forecasting framework that combines Large Language Models (LLMs) and Time Series Foundation Models (TSFMs). It generates realistic multimodal datasets by annotating real-world time series with LLMs and aligns the two models through staged fine‑tuning: first using Group Relative Policy Optimization to improve the LLM’s covariate generation, then fine‑tuning the TSFM on those covariates. Experiments on synthetic and real benchmarks across finance, economics, weather, traffic, and security show that CoCo can outperform state‑of‑the‑art TSFMs and LLM forecasters by up to 12% MAE.

arXiv Machine Learning
Aug 19

TiMi: Empower Time Series Transformers with Multimodal Mixture of Experts

The paper introduces TiMi, a framework that enhances time series transformers with a Multimodal Mixture-of-Experts (MMoE) module to incorporate multimodal data, especially textual information, into forecasting. TiMi leverages large language models to generate future inferences that guide predictions, eliminating the need for explicit representation alignment. Experiments show TiMi achieves state‑of‑the‑art performance on sixteen real‑world multimodal forecasting benchmarks, outperforming advanced baselines while maintaining adaptability and interpretability.

By Jiafeng Lin, Yuxuan Wang, Huakun Luo, Jianmin Wang, Zhongyi Pei
arXiv Machine Learning
Oct 28

TimeWorld: Towards Action-Conditioned Multimodal World Models for Time Series Forecasting

TimeWorld introduces a plug‑in framework for action‑conditioned multimodal world models in time‑series forecasting. It builds on pretrained time‑series foundation models (TSFMs) and adds a Prototype‑Guided Latent Modulation module to embed textual actions into temporal dynamics, along with an Action Contrastive Learning component to sharpen action‑specific response modeling. The authors also present TSWM‑Bench, a cross‑domain benchmark of seven real‑world datasets with textual interventions, showing that simple text‑prefix adaptations outperform conventional multimodal forecasters and that pretrained TSFMs already encode useful world knowledge for action‑conditioned predictions.

By Hang Ni, Weijia Zhang, Hao Liu
arXiv Machine Learning
Sep 24

ChronoSteer: Bridging Large Language Model and Time Series Foundation Model via Synthetic Cross-Modal Alignment Dataset

ChronoSteer is a decoupled agentic framework that bridges large language models and time series foundation models by learning cross‑modal alignment from synthetic paired supervision. It converts textual events into revision instructions that steer a frozen time‑series model, discretizes these instructions into a compact codebook to reduce semantic divergence, and then refines the predictions with a two‑stage training strategy. The authors also release a leakage‑controlled multimodal benchmark and report a 25.8% improvement in zero‑shot prediction accuracy over the unimodal backbone.

By Chengsen Wang, Qi Qi, Zhongwen Rao, Lujia Pan, Jingyu Wang
arXiv AI
6d ago

LLM-Integrated Bayesian State Space Models for Multimodal Time-Series Forecasting

The paper introduces LLM-Integrated Bayesian State Space Models (LBS) for multimodal time-series forecasting, combining a state space model backbone with a pretrained large language model to handle both numerical and textual data. LBS allows flexible lookback and forecast windows, principled uncertainty quantification, and improved temporal generalization. Experiments on the TextTimeCorpus benchmark show a 13.20% performance gain over the previous state‑of‑the‑art while providing human‑readable forecast summaries.

By Sungjun Cho, Changho Shin, Suenggwan Jo, Xinya Yan, Shourjo Aditya Chaudhuri, Frederic Sala
arXiv Machine Learning
Oct 23

WhatIf-Bench: Benchmarking Intervention-Aware Time Series Forecasting

WhatIf-Bench is a semi‑synthetic benchmark that tests how well time‑series forecasters use covariates to predict a target’s response to future events. It generates 37,665 tasks from mechanistic simulators of data centers, power grids, road traffic, and water networks, varying covariate numbers, historical events, and event length. Evaluation shows large‑language models outperform the best time‑series foundation models, with all models performing well on replayed events but struggling on novel covariate settings, highlighting generalization as the main challenge.

By Arjun Ashok, Mihir Parmar, Palash Goyal, Bhavana Dalvi Mishra, Chun-Liang Li, Irina Rish, Alexandre Drouin, Jinsung Yoon, Tomas Pfister
arXiv AI
Aug 25

NeST: Neighborhood-aware semantic alignment and temporal modulation for LLM based time series forecasting

NeST is a framework that adapts large language models (LLMs) for continuous time‑series forecasting by creating neighborhood‑aware text prototypes and aligning them with temporal representations through a nearest‑neighbor contrastive objective. It retrieves the most relevant prototypes and uses them to conditionally modulate time‑series features, enabling more effective integration of textual and temporal information. Experiments show that NeST outperforms state‑of‑the‑art methods on eight benchmarks, reduces MSE by 1.2% for long‑term forecasting, improves zero‑shot forecasting by 4.9%, and boosts R² by 3.3% on a real‑world photovoltaic power forecasting task.

By Jayanie Bogahawatte, Sachith Seneviratne, Maneesha Perera, Saman Halgamuge
Hugging Face Trending Papers
Jul 7

RMISC: A Large-scale Real-world Multivariate Corpus for Time Series Foundation Models

Recent years have witnessed the emergence of multivariate modeling using time series foundation models (TSFMs), which achieve advanced zero-shot generalization. Modern multivariate TSFMs are predominantly pretrained on multivariate synthetic data, which is easier to scale but may fail to capture the complex temporal dynamics and cross-variable relationships present in real-world time series.

arXiv AI
Sep 12

When Does Text Inform? Benchmarking Information-Theoretic Metrics for Multimodal Time-Series Forecasting

The paper introduces a synthetic benchmark for multimodal time‑series forecasting that evaluates how well text annotations contribute to predictions. By generating controlled signals with semantically correct, incorrect, and irrelevant annotations, the authors can precisely measure the true information content. Six mutual‑information estimators (KSG, MINE, InfoNCE, CCA, PID, and V‑information) are tested, all correctly ranking useful annotations and enabling annotation auditing without model training. The benchmark also highlights each estimator’s limitations and validates findings on seven real datasets, providing practical guidelines for metric implementation.

By Emma Andrews, Gianmarco Mengaldo
arXiv Machine Learning
Sep 29

WorldTS: World Modeling for Multimodal Covariate-aware Time Series Forecasting

WorldTS is a new forecasting framework that models latent dynamics conditioned on multimodal covariates to improve time‑series prediction. It uses a two‑stage training process: first learning latent state dynamics from historical data and covariates, then training a decoder to map predicted latent states back to future observations. Experiments on 21 real‑world datasets demonstrate the effectiveness of this approach.

By Yuhan Zhu, Xiangfei Qiu, Hanyin Cheng, Wangmeng Shen, Chenjuan Guo, Bin Yang, Jilin Hu, Christian S. Jensen