{"title":"First variation of functional Wulff shapes","authors":"Jacopo Ulivelli","doi":"10.1016/j.aim.2025.110529","DOIUrl":"10.1016/j.aim.2025.110529","url":null,"abstract":"<div><div>Using an approximation procedure we establish, for suitable perturbations, a weighted functional version of Aleksandrov's variational lemma in the family of convex functions with compact domain. The resulting formula is then applied to evaluate the first variation of a class of functionals on log-concave functions. In particular, we extend a recent result by Huang, Liu, Xi, and Zhao <span><span>[29]</span></span>.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110529"},"PeriodicalIF":1.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transfer principles for Galois cohomology and Serre's conjecture II","authors":"Diego Izquierdo , Giancarlo Lucchini Arteche","doi":"10.1016/j.aim.2025.110532","DOIUrl":"10.1016/j.aim.2025.110532","url":null,"abstract":"<div><div>In this article, we prove several transfer principles for the cohomological dimension of fields. Given a fixed field <em>K</em> with finite cohomological dimension <em>δ</em>, the two main ones allow to:<ul><li><span>-</span><span><div>construct totally ramified extensions of <em>K</em> with cohomological dimension <span><math><mo>≤</mo><mi>δ</mi><mo>−</mo><mn>1</mn></math></span> when <em>K</em> is a complete discrete valuation field;</div></span></li><li><span>-</span><span><div>construct algebraic extensions of <em>K</em> with cohomological dimension <span><math><mo>≤</mo><mi>δ</mi><mo>−</mo><mn>1</mn></math></span> and satisfying a norm condition.</div></span></li></ul> We then apply these results to Serre's conjecture II and to some variants for fields of any cohomological dimension that are inspired by conjectures of Kato and Kuzumaki. In particular, we prove that Serre's conjecture II for characteristic 0 fields implies Serre's conjecture II for positive characteristic fields.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110532"},"PeriodicalIF":1.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Blow-ups and normal bundles in connective and nonconnective derived geometries","authors":"Oren Ben-Bassat , Jeroen Hekking","doi":"10.1016/j.aim.2025.110530","DOIUrl":"10.1016/j.aim.2025.110530","url":null,"abstract":"<div><div>This work presents a generalization of derived blow-ups and of the derived deformation to the normal bundle from derived algebraic geometry to any geometric context. The latter is our proposed globalization of a derived algebraic context, itself a generalization of the theory of simplicial commutative rings and due to Bhatt–Mathew and Raksit.</div><div>One key difference between a geometric context and ordinary derived algebraic geometry is that the coordinate ring of an affine object in the former is not necessarily connective. When constructing generalized blow-ups, this not only turns out to be remarkably convenient, but also leads to a wider existence result. Indeed, we show that the derived Rees algebra and the derived blow-up exist for any affine morphism of stacks in a given geometric context. However, in general the derived Rees algebra will no longer be connective, hence in general the derived blow-up will not live in the connective part of the theory. Unsurprisingly, this can be solved by restricting the input to closed immersions. The proof of the latter statement uses a derived deformation to the normal bundle in any given geometric context, which is also of independent interest.</div><div>Besides the geometric context which extends algebraic geometry, the second main example of a geometric context is an extension of analytic geometry as based on categories of Ind-Banach spaces or modules. The latter is a recent construction, and includes many different flavors of analytic geometry, such as complex analytic geometry, non-Archimedean rigid analytic geometry and analytic geometry over the integers. The present work thus provides derived blow-ups and a derived deformation to the normal bundle in all of these, which is expected to have many applications.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110530"},"PeriodicalIF":1.5,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"K-moduli spaces of log Del Pezzo pairs","authors":"Long Pan , Fei Si , Haoyu Wu","doi":"10.1016/j.aim.2025.110536","DOIUrl":"10.1016/j.aim.2025.110536","url":null,"abstract":"<div><div>We establish the full explicit wall-crossings for K-moduli space <span><math><msup><mrow><mover><mrow><mi>P</mi></mrow><mo>‾</mo></mover></mrow><mrow><mi>K</mi></mrow></msup><mo>(</mo><mi>c</mi><mo>)</mo></math></span> of degree 8 del Pezzo pairs <span><math><mo>(</mo><mi>X</mi><mo>,</mo><mi>c</mi><mi>C</mi><mo>)</mo></math></span>, where generically <span><math><mi>X</mi><mo>≅</mo><msub><mrow><mi>F</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><mi>C</mi><mo>∼</mo><mo>−</mo><mn>2</mn><msub><mrow><mi>K</mi></mrow><mrow><mi>X</mi></mrow></msub></math></span>. We also show that the K-moduli spaces <span><math><msup><mrow><mover><mrow><mi>P</mi></mrow><mo>‾</mo></mover></mrow><mrow><mi>K</mi></mrow></msup><mo>(</mo><mi>c</mi><mo>)</mo></math></span> coincide with the Hassett-Keel-Looijenga (HKL) models <span><math><mi>F</mi><mo>(</mo><mi>s</mi><mo>)</mo></math></span> of an 18-dimensional locally symmetric space associated with the lattice <span><math><msub><mrow><mi>E</mi></mrow><mrow><mn>8</mn></mrow></msub><mo>⊕</mo><msup><mrow><mi>U</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>⊕</mo><msub><mrow><mi>E</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>⊕</mo><msub><mrow><mi>A</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> under the transformation <span><math><mi>s</mi><mo>(</mo><mi>c</mi><mo>)</mo><mo>=</mo><mfrac><mrow><mn>1</mn><mo>−</mo><mn>2</mn><mi>c</mi></mrow><mrow><mn>56</mn><mi>c</mi><mo>−</mo><mn>4</mn></mrow></mfrac></math></span>. This implies that the K-moduli spaces interpolate the GIT partial compactification and the Baily-Borel compactification for the moduli space of smooth Del Pezzo pairs. Some discussions concerning the relationship to KSBA moduli spaces are also provided.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"481 ","pages":"Article 110536"},"PeriodicalIF":1.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal version of the fundamental theorem of chronogeometry","authors":"Michiya Mori , Peter Šemrl","doi":"10.1016/j.aim.2025.110528","DOIUrl":"10.1016/j.aim.2025.110528","url":null,"abstract":"<div><div>We study lightlikeness preserving mappings from the 4-dimensional Minkowski spacetime <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> to itself under no additional regularity assumptions like continuity, surjectivity, or injectivity. We prove that such a mapping <em>ϕ</em> satisfies one of the following three conditions.<ul><li><span>(1)</span><span><div>The mapping <em>ϕ</em> can be written as a composition of a Lorentz transformation, a multiplication by a positive scalar, and a translation.</div></span></li><li><span>(2)</span><span><div>There is an event <span><math><mi>r</mi><mo>∈</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> such that <span><math><mi>ϕ</mi><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>∖</mo><mo>{</mo><mi>r</mi><mo>}</mo><mo>)</mo></math></span> is contained in one light cone.</div></span></li><li><span>(3)</span><span><div>There is a lightlike line <em>ℓ</em> such that <span><math><mi>ϕ</mi><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>∖</mo><mi>ℓ</mi><mo>)</mo></math></span> is contained in another lightlike line.</div></span></li></ul> Here, a line that is contained in some light cone in <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> is called a lightlike line. We also give several similar results on mappings defined on a certain subset of <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> or the compactification of <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span>.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110528"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A model for planar compacta and rational Julia sets","authors":"Jun Luo , Yi Yang , Xiaoting Yao","doi":"10.1016/j.aim.2025.110531","DOIUrl":"10.1016/j.aim.2025.110531","url":null,"abstract":"<div><div>A <strong>Peano compactum</strong> means a compact metric space having locally connected components such that at most finitely many of them are of diameter greater than any fixed number <span><math><mi>C</mi><mo>></mo><mn>0</mn></math></span>. Given a compactum <em>K</em> in the extended complex plane <span><math><mover><mrow><mi>C</mi></mrow><mrow><mo>ˆ</mo></mrow></mover></math></span>, it is known that there is a finest upper semi-continuous decomposition of <em>K</em> into subcontinua such that the resulting quotient space is a Peano compactum. We call this decomposition the <strong>core decomposition</strong> of <em>K</em> with Peano quotient and its elements <strong>atoms of</strong> <em>K</em>. We show that for any branched covering <span><math><mi>f</mi><mo>:</mo><mover><mrow><mi>C</mi></mrow><mrow><mo>ˆ</mo></mrow></mover><mo>→</mo><mover><mrow><mi>C</mi></mrow><mrow><mo>ˆ</mo></mrow></mover></math></span> and any atom <em>d</em> of <span><math><msup><mrow><mi>f</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>(</mo><mi>K</mi><mo>)</mo></math></span>, the image <span><math><mi>f</mi><mo>(</mo><mi>d</mi><mo>)</mo></math></span> is an atom of <em>K</em>. Since rational functions are branched coverings, our result extends earlier ones that are restricted to more limited cases, requiring that <em>f</em> be a polynomial with <span><math><msup><mrow><mi>f</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>(</mo><mi>K</mi><mo>)</mo><mo>=</mo><mi>K</mi></math></span>.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110531"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hugo Araújo , Carlos Gustavo Moreira , Alex Zamudio Espinosa
{"title":"Stable intersections of conformal regular Cantor sets with large Hausdorff dimensions","authors":"Hugo Araújo , Carlos Gustavo Moreira , Alex Zamudio Espinosa","doi":"10.1016/j.aim.2025.110507","DOIUrl":"10.1016/j.aim.2025.110507","url":null,"abstract":"<div><div>In this paper we prove that among pairs <span><math><mi>K</mi><mo>,</mo><mspace></mspace><msup><mrow><mi>K</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>⊂</mo><mi>C</mi></math></span> of conformal dynamically defined Cantor sets with sum of Hausdorff dimensions <span><math><mi>H</mi><mi>D</mi><mo>(</mo><mi>K</mi><mo>)</mo><mo>+</mo><mi>H</mi><mi>D</mi><mo>(</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>)</mo><mo>></mo><mn>2</mn></math></span>, there is an open and dense subset of such pairs verifying <span><math><mtext>int</mtext><mo>(</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>−</mo><mi>K</mi><mo>)</mo><mo>≠</mo><mo>∅</mo></math></span>. This is motivated by the work <span><span>[11]</span></span>, where Moreira and Yoccoz proved a similar statement for dynamically defined Cantor sets in the real line. Here we adapt their argument to the context of conformal Cantor sets in the complex plane, this requires the introduction of several new concepts and a more detailed analysis in some parts of the argument.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110507"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah Brauner , Christopher Eur , Elizabeth Pratt , Raluca Vlad
{"title":"Wondertopes","authors":"Sarah Brauner , Christopher Eur , Elizabeth Pratt , Raluca Vlad","doi":"10.1016/j.aim.2025.110516","DOIUrl":"10.1016/j.aim.2025.110516","url":null,"abstract":"<div><div>Positive geometries were introduced by Arkani-Hamed–Bai–Lam in their study of scattering amplitudes in theoretical physics. We show that a positive geometry from a polytope admits a log resolution of singularities to another positive geometry. Our result states that the regions in a wonderful compactification of a hyperplane arrangement complement, which we call <em>wondertopes</em>, are positive geometries. A familiar wondertope is the curvy associahedron which tiles the moduli space of <em>n</em>-pointed stable rational curves <span><math><msub><mrow><mover><mrow><mi>M</mi></mrow><mo>‾</mo></mover></mrow><mrow><mn>0</mn><mo>,</mo><mi>n</mi></mrow></msub></math></span>. Thus our work generalizes the known positive geometry <span><math><msub><mrow><mover><mrow><mi>M</mi></mrow><mo>‾</mo></mover></mrow><mrow><mn>0</mn><mo>,</mo><mi>n</mi></mrow></msub></math></span>.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110516"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"W⁎-superrigidity for groups with infinite center","authors":"Milan Donvil , Stefaan Vaes","doi":"10.1016/j.aim.2025.110527","DOIUrl":"10.1016/j.aim.2025.110527","url":null,"abstract":"<div><div>We construct discrete groups <em>G</em> with infinite center that are nevertheless W<sup>⁎</sup>-superrigid, meaning that the group von Neumann algebra <span><math><mi>L</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> fully remembers the group <em>G</em>. We obtain these rigidity results both up to isomorphisms and up to virtual isomorphisms of the groups and their von Neumann algebras. Our methods combine rigidity results for the quotient of these groups by their center with rigidity results for their 2-cohomology.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110527"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Point counting on Igusa varieties for function fields","authors":"Paul Hamacher , Wansu Kim","doi":"10.1016/j.aim.2025.110517","DOIUrl":"10.1016/j.aim.2025.110517","url":null,"abstract":"<div><div>Igusa varieties over the special fibre of Shimura varieties have demonstrated many applications to the Langlands program via Mantovan's formula and Shin's point counting method. In this paper we study Igusa varieties over the moduli stack of global <span><math><mi>G</mi></math></span>-shtukas and (under certain conditions) calculate the Hecke action on its cohomology. As part of their construction we prove novel results about local <em>G</em>-shtukas in both equal and unequal characteristic and also discuss application of these results to Barsotti-Tate groups and Shimura varieties.</div></div>","PeriodicalId":50860,"journal":{"name":"Advances in Mathematics","volume":"480 ","pages":"Article 110517"},"PeriodicalIF":1.5,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}