{"title":"Unstable homotopy groups and Lie algebras.","authors":"Mark Behrens, Connor Malin","doi":"10.1098/rsta.2024.0396","DOIUrl":"https://doi.org/10.1098/rsta.2024.0396","url":null,"abstract":"<p><p>We survey the role of Lie algebras in the study of unstable homotopy groups. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148841037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Atiyah-Sutcliffe conjecture and En algebras.","authors":"Lorenzo Guerra, Paolo Salvatore","doi":"10.1098/rsta.2024.0406","DOIUrl":"https://doi.org/10.1098/rsta.2024.0406","url":null,"abstract":"<p><p>We show that a certain conjecture by Atiyah and Sutcliffe implies the existence of an E3-algebra (respectively E2-algebra) structure on the disjoint union of all complex (respectively real) full flag manifolds modulo symmetric groups. Moreover, we show that these structures are liftings of exotic E3 (respectively E2) structures on the free E∞-algebras on BU(1)+ (respectively BO(1)+), that do not extend to E4 (respectively E3) structures. We also provide some (co)homological calculations supporting the conjecture. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148841000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Applications of the circle product with a right Com-module to the theory of commutative ring spectra.","authors":"Nicholas John Kuhn","doi":"10.1098/rsta.2024.0404","DOIUrl":"https://doi.org/10.1098/rsta.2024.0404","url":null,"abstract":"<p><p>If Com is the reduced commutative operad, the category of Com-algebras in spectra is the category of non-unital commutative ring spectra. The theme of this survey is that many important constructions on Com-algebras are given by taking the derived circle product with well-chosen right Com-modules. We show that examples of constructions arising this way include K⊗I, the tensor product of a based space K with such an algebra I, and TQ(I), the Topological André-Quillen homology spectrum of I. We then show how filtrations of right Com-modules can be used to filter such constructions. A natural decreasing filtration on right Com-modules is described. When specialized to the Com-bimodule Com, this defines the augmentation ideal tower of I, built out of the extended powers of TQ(I). A less studied natural increasing filtration is described. When specialized to the right Com-module used to define TQ(I), one gets a filtration on TQ(I) built out of I and the spaces in the Lie cooperad. There are two versions of this in the literature, and our setting here makes it easy to prove that these agree. Much of this applies with Com replaced by a more general reduced operad, and we make a few remarks about this. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The animation of the opposite of finite sets.","authors":"Benjamin Antieau","doi":"10.1098/rsta.2024.0395","DOIUrl":"https://doi.org/10.1098/rsta.2024.0395","url":null,"abstract":"<p><p>We give a direct proof of the fact that the animation of the category Finop is a 1-category. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148841036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lie algebras and the (co)homology of configuration spaces.","authors":"Ben Knudsen","doi":"10.1098/rsta.2024.0402","DOIUrl":"https://doi.org/10.1098/rsta.2024.0402","url":null,"abstract":"<p><p>We survey decades of research identifying the (co)homology of configuration spaces with Lie algebra (co)homology. The different routes to this one proto-theorem offer genuinely different explanations of its truth, and we attempt to convey some sense of the conceptual core of each perspective. We close with a list of problems. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lie structures in homotopy and isotopy calculi.","authors":"Danica Kosanović","doi":"10.1098/rsta.2024.0403","DOIUrl":"https://doi.org/10.1098/rsta.2024.0403","url":null,"abstract":"<p><p>We establish compatibility of Lie structures that appear in homotopy calculus of functors and isotopy calculus of embeddings. On one hand, we give a new proof of the Johnson-Arone-Mahowald result describing the layers of the Goodwillie tower of the identity functor, and we directly compare the spectral Lie bracket with the classical Samelson (Whitehead) bracket on spaces. On the other hand, we geometrically define a bracket on the layers of the embedding calculus tower for embeddings of arcs. These results are unified through the same technical tool, a newly defined bracket on total homotopy fibres of collapsing cubes of wedge sums. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Higher holonomy for curved L∞-algebras 1: simplicial methods.","authors":"Ezra Getzler","doi":"10.1098/rsta.2024.0400","DOIUrl":"https://doi.org/10.1098/rsta.2024.0400","url":null,"abstract":"<p><p>We construct a natural morphism ρ from the nerve MC∙(L)=MC(Ω∙⊗^L) of a pronilpotent curved L∞-algebra L to the simplicial subset γ∙(L)=MC(Ω∙⊗^L,s∙) of Maurer-Cartan element satisfying the Dupont gauge condition. This morphism equals the identity on the image of the inclusion γ∙(L)↪MC∙(L). The proof uses the extension of Berglund's homotopical perturbation theory for L∞-algebras to curved L∞-algebras. The morphism ρ equals the holonomy for nilpotent Lie algebras. In a sequel to this paper, we use a cubical analogue ρ◻ of ρ to identify ρ with higher holonomy for semiabelian curved L∞-algebras. This article is part of the theme issue 'Derived Lie algebras in geometry and topology'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2328","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Residual distribution predictive systems.","authors":"Sam Allen, Enrico Pescara, Johanna Ziegel","doi":"10.1098/rsta.2025.0080","DOIUrl":"https://doi.org/10.1098/rsta.2025.0080","url":null,"abstract":"<p><p>Conformal predictive systems are sets of predictive distributions with theoretical out-of-sample calibration guarantees. The calibration guarantees are typically that the set contains a forecast distribution whose prediction intervals exhibit the correct marginal coverage at all levels. Conformal predictive systems are constructed using conformity measures that quantify how well possible outcomes conform with historical data. However, alternative methods have been proposed to construct predictive systems with more appealing theoretical properties. We study an approach to construct predictive systems that we term residual distribution predictive systems (RDPSs). In the split conformal setting, this approach nests conformal predictive systems with a popular class of conformity measures, providing an alternative perspective on the classical approach. In the full conformal setting, the two approaches differ, and the new approach has the advantage that it does not rely on a conformity measure satisfying fairly stringent requirements to ensure that the predictive system is well-defined; it can readily be implemented alongside any point-valued regression method to yield predictive systems with out-of-sample calibration guarantees. The empirical performance of this approach is assessed using simulated data, where it is found to perform competitively with conformal predictive systems. However, the new approach offers considerable scope for implementation with alternative regression methods. This article is part of the theme issue 'Advancing uncertainty quantification in AI systems'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2327","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148831280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Uncertainty quantification using conformal prediction for mesh-based simulations.","authors":"Samira Mabtoul, Izhar Ali, Shen Shyang Ho","doi":"10.1098/rsta.2025.0076","DOIUrl":"https://doi.org/10.1098/rsta.2025.0076","url":null,"abstract":"<p><p>Machine learning surrogates for computational fluid dynamics (CFD) achieve substantial speedups but lack uncertainty quantification (UQ). We develop a post hoc conformal prediction (CP) framework that wraps any trained graph neural network (GNN) surrogate to produce prediction sets with coverage near-nominal levels. Using MeshGraphNet on two benchmark datasets-CylinderFlow (2D velocity) and Flag (3D position), we compare five prediction-set geometries. Our componentwise adaptive (CW-Adaptive) method emerges as the robust universal choice, achieving 28%-55% smaller prediction sets versus ℓ2 balls across both datasets at 95% confidence while maintaining near-nominal coverage. By learning per-component scales from domain-aware features, CW-Adaptive captures both spatial heterogeneity and anisotropic error structure-outperforming Mahalanobis ellipsoids that provide only modest gains (approx. 14%) when residuals are anisotropic and inflate sets otherwise. All methods achieve coverage within 2%-3% of nominal despite distribution drift in mesh-based simulations that violates exchangeability assumption. This article is part of the theme issue 'Advancing uncertainty quantification in AI systems'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2327","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148831284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luben Miguel Cruz Cabezas, Vagner Silva Santos, Thiago Rodrigo Ramos, Pedro L C Rodrigues, Rafael Izbicki
{"title":"CP4SBI: local conformal calibration of credible sets in simulation-based inference.","authors":"Luben Miguel Cruz Cabezas, Vagner Silva Santos, Thiago Rodrigo Ramos, Pedro L C Rodrigues, Rafael Izbicki","doi":"10.1098/rsta.2025.0069","DOIUrl":"https://doi.org/10.1098/rsta.2025.0069","url":null,"abstract":"<p><p>Current experimental scientists have been increasingly relying on simulation-based inference (SBI) to invert complex nonlinear models with intractable likelihoods. However, posterior approximations obtained with SBI are often miscalibrated, causing credible regions to undercover true parameters. We develop CP4SBI, a model-agnostic conformal calibration framework that constructs credible sets with local Bayesian coverage. Our two proposed variants, namely local calibration via regression trees and cumulative distribution function CDF-based calibration, enable finite-sample local coverage guarantees for any scoring function, including highest posterior density (HPD), symmetric and quantile-based regions. Experiments on widely used SBI benchmarks demonstrate that our approach improves the quality of uncertainty quantification for neural posterior estimators (NPEs) using both normalizing flows and score-diffusion modelling. This article is part of the theme issue 'Advancing uncertainty quantification in AI systems'.</p>","PeriodicalId":19879,"journal":{"name":"Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences","volume":"384 2327","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148831315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}