Evan Chen, Kenny Lau, Seewoo Lee, Ken Ono, Jujian Zhang
{"title":"Almost all primes are partially regular","authors":"Evan Chen, Kenny Lau, Seewoo Lee, Ken Ono, Jujian Zhang","doi":"10.1007/s00013-026-02261-y","DOIUrl":"10.1007/s00013-026-02261-y","url":null,"abstract":"<div><p>For odd primes <i>p</i>, we let <span>(K_p:=mathbb {Q}(zeta _p))</span> be the <i>p</i>th cyclotomic field and let <span>(omega )</span> denote its Teichmüller character. For <span>(alpha >1/2)</span>, we say that an odd prime <i>p</i> is <i>partially regular</i> if the eigenspaces of the <i>p</i>-Sylow subgroup of <span>({{,textrm{Cl},}}(K_p))</span> under the Galois action vanish for all characters <span>(omega ^{p-2k})</span> with </p><div><div><span>$$begin{aligned} 2le 2k le frac{sqrt{p}}{(log p)^{alpha }}. end{aligned}$$</span></div><div>\u0000 (1)\u0000 </div></div><p>Equivalently, <span>(pnot mid {{,textrm{num},}}(B_{2k}))</span> throughout this range. We prove that a density-one subset of primes is partially regular in this sense. By <i>Leopoldt reflection</i>, this yields a <i>partial Vandiver theorem</i>: for a density-one set of primes <i>p</i>, the even eigenspaces <span>(A_p(omega ^{2k}))</span> vanish for all even 2<i>k</i> satisfying (1). This result has consequences for Kubota–Leopoldt <i>p</i>-adic <i>L</i>-functions, congruences between cusp forms and Eisenstein series, and <i>p</i>-torsion in algebraic <i>K</i>-groups. The theorem proving partial regularity for almost all <i>p</i> is fully formalized in Lean/Mathlib and was produced automatically by AxiomProver from a natural-language statement of the conjecture.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 2","pages":"165 - 178"},"PeriodicalIF":0.6,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Patterns in trees and quantum automorphism groups","authors":"Lucas Alger, Julie Capron, Félix de la Salle","doi":"10.1007/s00013-026-02260-z","DOIUrl":"10.1007/s00013-026-02260-z","url":null,"abstract":"<div><p>We prove that given a fixed finite tree <i>P</i>, almost all trees contain <i>P</i> as a subtree. Moreover, the inclusion can be made so that it induces an embedding of the corresponding (quantum) automorphism groups, thereby providing generic properties of the latter.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"83 - 93"},"PeriodicalIF":0.6,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00013-026-02260-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Algebraic K-groups of (mathbb {Q}(sqrt{pm p})) and the digits of 1/p","authors":"Reza Taleb","doi":"10.1007/s00013-026-02244-z","DOIUrl":"10.1007/s00013-026-02244-z","url":null,"abstract":"<div><p>Let <span>(nge 1)</span> be an integer, let <span>(pge 5)</span> be a prime number, let <span>(1<g<p)</span> be a primitive root modulo <i>p</i>, and let <i>F</i> denote either the quadratic field <span>(mathbb {Q}(sqrt{p}))</span> in the case <i>n</i> is even and <span>(pequiv 1 pmod {4})</span>, or <span>(mathbb {Q}(sqrt{-p}))</span> in the case <i>n</i> is odd and <span>(pequiv 3 pmod {4})</span>. For <span>(n=1)</span>, the class number of the field <i>F</i> is expressed in terms of the alternating sum of the digits of the repetend in the <i>g</i>-adic expansion of 1/<i>p</i> in Girstmair (Am Math Mon 101(10):997–1001, 1994; Acta Arith 67(4):381–386, 1994), and Murty and Thangadurai (Proc Amer Math Soc 139(4):1277–1289, 2011). In this paper, the orders of even algebraic <i>K</i>-groups <span>(K_{2n-2}(mathcal {O}_F))</span>, for the ring of integers <span>(mathcal {O}_F)</span> of <i>F</i>, are expressed in terms of the digits of the repetend of the <i>g</i>-adic expansion of 1/<i>p</i> for any integer <span>(nge 2)</span>.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"47 - 57"},"PeriodicalIF":0.6,"publicationDate":"2026-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Monogenic strictly-Perron polynomials","authors":"Lenny Jones","doi":"10.1007/s00013-026-02265-8","DOIUrl":"10.1007/s00013-026-02265-8","url":null,"abstract":"<div><p>A monic polynomial <span>(f(x)in {mathbb Z}[x])</span> of degree <i>n</i> is called <i>monogenic</i> if <i>f</i>(<i>x</i>) is irreducible over <span>({mathbb Q})</span> and <span>({1,theta ,theta ^2,ldots ,theta ^{n-1}})</span> is a basis for the ring of integers of <span>({mathbb Q}(theta ))</span>, where <span>(f(theta )=0)</span>. A <i>strictly-Perron</i> polynomial is the minimal polynomial of a Perron number <span>(lambda )</span> such that <span>(lambda )</span> is neither a Pisot number, an anti-Pisot number, nor a Salem number. For any natural number <span>(nge 2)</span>, we prove that there exist infinitely many monogenic strictly-Perron polynomials of degree <i>n</i>.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"25 - 32"},"PeriodicalIF":0.6,"publicationDate":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00013-026-02265-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Euler characteristic of closed manifolds with almost nonnegative curvature operator","authors":"Jingbin Cai","doi":"10.1007/s00013-026-02254-x","DOIUrl":"10.1007/s00013-026-02254-x","url":null,"abstract":"<div><p>We study closed manifolds with almost nonnegative curvature operator and address a question of Herrmann–Sebastian–Tuschmann concerning the sign of their Euler characteristic. Our main result shows that if a closed 2<i>n</i>-dimensional manifold admits an almost nonnegative curvature operator together with a uniform upper bound on the curvature operator, then its Euler characteristic is nonnegative. In addition, under an ANCO-type condition and assuming that the fundamental group is infinite, we prove vanishing results for the Euler characteristic, the signature, and, in the spin case, the <span>(widehat{A})</span>-genus, extending recent work of Chen–Ge–Han from almost nonnegative Ricci curvature to the curvature operator setting.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"59 - 70"},"PeriodicalIF":0.6,"publicationDate":"2026-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Non-linearizable root group data","authors":"Sebastian Bischof","doi":"10.1007/s00013-026-02253-y","DOIUrl":"10.1007/s00013-026-02253-y","url":null,"abstract":"<div><p>An RGD system <span>(mathcal {D})</span> is called <i>linear w.r.t. a root basis </i><span>(mathcal {B})</span> if the commutation relations between the root groups of <span>(mathcal {D})</span> are ‘linear’ in a certain sense. Moreover, <span>(mathcal {D})</span> is called <i>linearizable</i> if there exists a root basis <span>(mathcal {B})</span> such that <span>(mathcal {D})</span> is linear w.r.t. <span>(mathcal {B})</span>. For many examples of RGD systems it is easy to see that they are linear w.r.t. a concrete root basis. To the best of our knowledge, it was unclear whether RGD systems exist which are not linearizable. In this article, we show that there exist uncountably many RGD systems which are not linearizable. In particular, we provide the first explicit example of such an RGD system. This expands the quote from Rémy that axiom <span>(text {(RGD1)}_{textrm{lin}})</span> is not only a strengthening of axiom (RGD1), but is in fact stronger than it. We show that non-linearizability appears in examples of universal type, and also in examples of 2-spherical type. For the examples of universal type, we construct an uncountable family of non-linearizable RGD systems, and for the examples of 2-spherical type, we show that the RGD systems of type (4, 4, 4) recently constructed by the author provide uncountably many non-linearizable RGD systems.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"126 6","pages":"557 - 570"},"PeriodicalIF":0.6,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00013-026-02253-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148285465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Brownian convergence of planar domains and stability of the planar Skorokhod embedding problem","authors":"Maher Boudabra, Mrabet Becher, Fathi Haggui","doi":"10.1007/s00013-026-02258-7","DOIUrl":"10.1007/s00013-026-02258-7","url":null,"abstract":"<div><p>We present a numerical framework for approximating the <span>(mu )</span>-domain in the planar Skorokhod embedding problem PSEP, recently introduced in Gross (Electron Commun Probab 24:1–11, 2019). We show that under weak convergence of a sequence of probability measures <span>((mu _{n})_{n})</span>, the corresponding sequence of <span>(mu _{n})</span>-domains converges, in an appropriate sense, to the domain associated with the limit measure <span>(mu )</span>. In addition, we provide implementation strategies, convergence rate estimates, and a numerical example. The method is robust and versatile, offering a concrete computational approach for the approximation of <span>(mu )</span>-domains. As part of this analysis, we introduce a novel mode of convergence for planar domains via planar Brownian motion, which we call <i>p</i>-Brownian convergence.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"95 - 111"},"PeriodicalIF":0.6,"publicationDate":"2026-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148613272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"R-triviality for adjoint classical groups of type C","authors":"M. Archita","doi":"10.1007/s00013-026-02263-w","DOIUrl":"10.1007/s00013-026-02263-w","url":null,"abstract":"<div><p>For a central simple algebra with a symplectic involution <span>((A,sigma ))</span> over a field of characteristic different from 2, we show that its group of projective similitudes <span>(textbf{PSim}(A,sigma ))</span> is <i>R</i>-trivial in two new cases.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"127 1","pages":"1 - 7"},"PeriodicalIF":0.6,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148614987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Boundary limit of the integral kernels of some holomorphic semigroups","authors":"Haimeng Luo, Shiliang Zhao","doi":"10.1007/s00013-026-02250-1","DOIUrl":"10.1007/s00013-026-02250-1","url":null,"abstract":"<div><p>Let <i>H</i> be a self-adjoint operator on <span>(L^2(X))</span> and generate a bounded holomorphic semigroup of angle <span>(frac{pi }{2})</span>. In this paper, we study the following questions. First, if <span>(e^{-zH})</span> is an integral operator with integral kernel <i>K</i>(<i>z</i>, <i>x</i>, <i>y</i>), then, under what circumstances, <i>K</i>(<i>z</i>, <i>x</i>, <i>y</i>) has a boundary limit and the limit becomes the integral kernel of <span>(e^{-itH})</span>. On the other hand, if <span>(e^{-itH})</span> is an integral operator with integral kernel <i>K</i>(<i>it</i>, <i>x</i>, <i>y</i>), whether <span>( e^{-zH} )</span> is also an integral operator and how to construct the integral kernel from <i>K</i>(<i>it</i>, <i>x</i>, <i>y</i>), if it exists. Finally, we apply the results to study the joint continuity of the integral kernel of <span>(e^{-itH})</span> where <span>(H= -Delta + V)</span> and <span>(Vin L^{2}(mathbb {R}^nu ))</span> such that the Fourier transform of <i>V</i> has compact support.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"126 6","pages":"635 - 647"},"PeriodicalIF":0.6,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148285470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Liouville points on rational affine varieties","authors":"Diego Marques","doi":"10.1007/s00013-026-02255-w","DOIUrl":"10.1007/s00013-026-02255-w","url":null,"abstract":"<div><p>In 2014, Kumar et al. (Arch Math (Basel) 102:59–70, 2014) proved the existence of uncountably many Liouville tuples whose exponentials are again Liouville and whose generated exponential fields have large transcendence degree. In this note, we extend their result to a geometric setting by requiring the Liouville tuples to satisfy algebraic constraints, namely to lie on prescribed rational affine varieties.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":"126 6","pages":"605 - 613"},"PeriodicalIF":0.6,"publicationDate":"2026-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00013-026-02255-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148285466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}