Epoch’s AI use in research explorer uses metadata and source text from arXiv and bioRxiv to track AI use acknowledgments in physics, statistics, mathematics, and biology. We use an AI model to read relevant passages in papers with AI keywords and decide whether the paper contains an AI use acknowledgment. We focus on use of Large Language Models (LLMs), rather than specialized AI tools, but we also track specialized AI tool use in biology.
The data is available on the GitHub repository for this project. Any questions can be directed to impacts@epoch.ai.
This explorer uses data from the following sources.
We thank arXiv and bioRxiv for their open-access interoperability. This project was not reviewed or approved by arXiv or bioRxiv, nor does it necessarily express or reflect their policies or opinions.
An arXiv paper belongs to a field according to its primary category.
We categorize physics papers into seven subfields, based on arXiv subfield categories: astrophysics (astro-ph), condensed matter (cond-mat), quantum physics (quant-ph), high-energy physics (hep-ex, hep-lat, hep-ph, hep-th), gravitation and cosmology (gr-qc), nuclear physics (nucl-ex, nucl-th), and other physics (the physics.* categories and math-ph).
The downloadable data keeps each arXiv category.
Mathematics and statistics papers are categorized according to their arXiv subfield categories. The statistics theory (stat.TH) subfield is an alias of the math.ST subfield, so theoretical statistics papers count under mathematics, not statistics.
We categorize biology papers into eight subfields, based on bioRxiv subfield categories: neuroscience and behavior; molecular and cell biology (cell, molecular and developmental biology, biochemistry, biophysics); computational biology (bioinformatics, systems biology); bioengineering and synthetic biology; microbiology and immunology; genetics, genomics and evolution; ecology and organismal biology (ecology, plant biology, zoology, paleontology); and biomedical and physiology (cancer biology, physiology, pharmacology and toxicology, pathology). The downloadable data keeps each bioRxiv category.
We sourced the full text of the most recent available version of each paper as of October 13, 2026. LLM use acknowledgments added in revisions are counted under the date of the first version of the paper.
We say that a paper acknowledges LLM use if it acknowledges the use of LLMs or unspecified AI tools for any purpose. We exclude the use of specialized AI tools such as AlphaFold from this count. We used the following process to identify acknowledgments of LLM use.
We use the OpenAI Decisions API to classify each LLM use acknowledgment into five use cases: research, code and computation, writing, literature review, and unspecified. A single LLM use acknowledgment can contain multiple use cases. The Decisions API uses GPT-6 Luna to read text and answer a decision question about the text. In our case, GPT-6 Luna reads passages containing an AI use acknowledgment and, for each use case, answers yes or no: was the LLM used for this purpose? The prompt for each use case is available on the GitHub repository.
We validated the acknowledgment identification and use case classification in two ways: against our AI use in math research explorer methodology and against a human classification.
We can compare results for every preprint against the AI use in math research explorer. The following table shows the agreement on whether a paper contains an AI use acknowledgment.
| Math explorer yes | Math explorer no | |
|---|---|---|
| Research explorer yes | 7,072 | 93 |
| Research explorer no | 69 | 155,009 |
The following table shows the agreement for the use-case classifications. Precision measures how many use cases identified by the research explorer methodology match those determined by the math explorer methodology. Recall measures how many of the use cases determined by the math explorer methodology were also detected by the research explorer methodology.
| Use case | Math explorer | Research explorer | Precision | Recall |
|---|---|---|---|---|
| Research | 4,657 | 4,431 | 94% | 90% |
| Writing | 4,650 | 4,736 | 94% | 96% |
| Literature review | 1,162 | 1,251 | 86% | 92% |
| Code and computation | 1,576 | 1,630 | 87% | 89% |
| Purpose not stated | 176 | 160 | 69% | 63% |
To estimate the accuracy of the model’s decisions on AI use, an Epoch researcher reviewed a sample of 238 decisions the model made in biology, physics, and statistics. In total, the human reviewer agreed with 226 of 238 decisions, giving an estimated accuracy of 95% on the sample. The human reviewer agreed with 56 out of 60 of the model’s decisions on LLM use for research in biology preprints, and 30 out of 30 of the model’s decisions on specialized AI tool use in biology preprints.
Large language models are not the only useful AI tools for science. AlphaFold, for example, is a notable specialized AI tool designed for scientific research. To compare LLM use and the use of specialized AI tools, we also track acknowledgments in bioRxiv preprints that acknowledge use of specialized AI tools. We used the following process.
This explorer uses preprints as a sample of the research papers in different scientific domains. We estimate how representative the preprints on arXiv and bioRxiv are for each domain. To do this, we identified top-tier journals in physics, mathematics, statistics, and biology, identified every research paper published in one of these journals from 2021 to 2025, and checked how many also appear on arXiv or bioRxiv.
| Field | Journals | Coverage |
|---|---|---|
| Physics | Physical Review Letters, Physical Review X, Nature Physics, Nature Astronomy, The Astrophysical Journal Letters, Nature Materials, Nature Nanotechnology, Classical and Quantum Gravity, PRX Quantum, npj Quantum Information, Journal of High Energy Physics, Physical Review C, Science, PNAS | 81% |
| Mathematics | Annals of Mathematics, Acta Mathematica, Inventiones Mathematicae, Journal of the AMS, Publications mathématiques de l’IHÉS | 97% |
| Statistics | Annals of Statistics, JASA, JRSS Series B, Biometrika, Annals of Applied Statistics, PNAS | 73% |
| Biology | Cell, Nature Genetics, Nature Neuroscience, Nature Microbiology, Nature Ecology & Evolution, Science, PNAS | 32% |
We also include an estimated breakdown of coverage by subfield. For the sake of this estimated breakdown, the arXiv subfield for papers published in journals was determined by GPT-5.6 Sol using the title, journal, OpenAlex topic, and, where available, the abstract of the paper.
Physics (subfields from a random sample of 6,281 papers)
| Subfield | Papers | On arXiv |
|---|---|---|
| High-energy physics | 1,740 | 99% |
| Gravitation and cosmology | 454 | 94% |
| Quantum physics | 629 | 91% |
| Astrophysics | 807 | 82% |
| Nuclear physics | 721 | 69% |
| Condensed matter | 1,099 | 66% |
| Other physics | 831 | 52% |
| All physics | 46,036 | 81% |
Mathematics (592 papers)
| Subfield | Papers | On arXiv |
|---|---|---|
| Algebraic geometry (math.AG) | 102 | 98% |
| Number theory (math.NT) | 73 | 92% |
| Analysis of PDEs (math.AP) | 63 | 98% |
| Dynamical systems (math.DS) | 50 | 94% |
| Differential geometry (math.DG) | 46 | 100% |
| Probability (math.PR) | 29 | 100% |
| Algebraic topology (math.AT) | 26 | 100% |
| Representation theory (math.RT) | 25 | 100% |
| Symplectic geometry (math.SG) | 23 | 100% |
| Geometric topology (math.GT) | 23 | 100% |
| Combinatorics (math.CO) | 22 | 100% |
| Group theory (math.GR) | 20 | 100% |
| 13 smaller categories (<20 papers each) | 90 | 96% |
| All mathematics | 592 | 97% |
Statistics (2,911 papers).
| Subfield | Papers | On arXiv |
|---|---|---|
| Computation (stat.CO) | 94 | 91% |
| Machine learning (stat.ML) | 158 | 86% |
| Methodology and theory (stat.ME + math.ST) | 2,374 | 73% |
| Applications (stat.AP) | 267 | 63% |
| All statistics | 2,911 | 73% |
Biology (17,579 papers).
| Subfield | Papers | On bioRxiv |
|---|---|---|
| Neuroscience and behavior | 3,712 | 37% |
| Computational biology | 553 | 36% |
| Molecular and cell biology | 4,679 | 33% |
| Genetics, genomics and evolution | 3,217 | 32% |
| Bioengineering and synthetic biology | 443 | 30% |
| Biomedical and physiology | 786 | 27% |
| Microbiology and immunology | 2,976 | 27% |
| Ecology and organismal biology | 1,194 | 25% |
| All biology | 17,579 | 32% |
The analysis of coverage on preprint servers suggests that, especially in biology, varying coverage of preprints by subfield may bias overall results. For instance, computational subfields of biology are better represented among biology preprints than experimental subfields, and are also more likely to acknowledge LLM use; this could lead us to overestimate LLM use in biology preprints overall.