{"title":"Log canonical pairs with conjecturally minimal volume","authors":"Louis Esser, Burt Totaro","doi":"10.1007/s00229-024-01588-6","DOIUrl":"https://doi.org/10.1007/s00229-024-01588-6","url":null,"abstract":"<p>We construct log canonical pairs (<i>X</i>, <i>B</i>) with <i>B</i> a nonzero reduced divisor and <span>(K_X+B)</span> ample that have the smallest known volume. We conjecture that our examples have the smallest volume in each dimension. The conjecture is true in dimension 2, by Liu and Shokurov. The examples are weighted projective hypersurfaces that are not quasi-smooth. We also develop an example for a related extremal problem. Esser constructed a klt Calabi–Yau variety which conjecturally has the smallest mld in each dimension (for example, mld 1/13 in dimension 2 and 1/311 in dimension 3). However, the example was only worked out completely in dimensions at most 18. We now prove the desired properties of Esser’s example in all dimensions (in particular, determining its mld).</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"44 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220394","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":"Regulator of the Hesse cubic curves and hypergeometric functions","authors":"Yusuke Nemoto","doi":"10.1007/s00229-024-01587-7","DOIUrl":"https://doi.org/10.1007/s00229-024-01587-7","url":null,"abstract":"<p>We construct some integral elements in the motivic cohomology of the Hesse cubic curves and express their regulators in terms of generalized hypergeometric functions and Kampé de Fériet hypergeometric functions. By using these hypergeometric expressions, we obtain numerical examples of the Bloch-Beilinson conjecture on special values of <i>L</i>-functions.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"143 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864397","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":"Cones of orthogonal Shimura subvarieties and equidistribution","authors":"Riccardo Zuffetti","doi":"10.1007/s00229-024-01586-8","DOIUrl":"https://doi.org/10.1007/s00229-024-01586-8","url":null,"abstract":"<p>Let <i>X</i> be an orthogonal Shimura variety, and let <span>(mathcal {C}^{textrm{ort}}_{r}(X))</span> be the cone generated by the cohomology classes of orthogonal Shimura subvarieties in <i>X</i> of dimension <i>r</i>. We investigate the asymptotic properties of the generating rays of <span>(mathcal {C}^{textrm{ort}}_{r}(X))</span> for large values of <i>r</i>. They accumulate towards rays generated by wedge products of the Kähler class of <i>X</i> and the fundamental class of an orthogonal Shimura subvariety. We also compare <span>(mathcal {C}^{textrm{ort}}_{r}(X))</span> with the cone generated by the special cycles of dimension <i>r</i>. The main ingredient to achieve the results above is the equidistribution of orthogonal Shimura subvarieties.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"26 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771976","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":"Rational fibered cubic fourfolds","authors":"Hanine Awada","doi":"10.1007/s00229-024-01585-9","DOIUrl":"https://doi.org/10.1007/s00229-024-01585-9","url":null,"abstract":"<p>Some classes of cubic fourfolds are birational to fibrations over <span>({mathbb {P}}^2)</span>, where the fibers are rational surfaces. This is the case for cubics containing a plane (resp. an elliptic ruled surface), where the fibers are quadric surfaces (resp. del Pezzo sextic surfaces). It is known that the rationality of these cubic hypersurfaces is related to the rationality of these surfaces over the function field of <span>({mathbb {P}}^2)</span> and to the existence of rational (multi)sections of the fibrations. We study, in the moduli space of cubic fourfolds, the intersection of the divisor <span>({mathcal {C}}_{8})</span> (resp. <span>({mathcal {C}}_{18})</span>) with <span>({mathcal {C}}_{14})</span>, <span>({mathcal {C}}_{26})</span> and <span>({mathcal {C}}_{38})</span>, whose elements are known to be rational cubic fourfolds. We provide descriptions of the irreducible components of these intersections and give new explicit examples of rational cubics fibered in (quartic, quintic) del Pezzo surfaces or in quadric surfaces over <span>({mathbb {P}}^2)</span>. We also investigate the existence of rational sections for these fibrations. Under some mild assumptions on the singularities of the fibers, these properties can be translated in terms of Brauer classes on certain surfaces.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"17 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141612266","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":"Weyl’s law for arbitrary archimedean type","authors":"Ayan Maiti","doi":"10.1007/s00229-024-01584-w","DOIUrl":"https://doi.org/10.1007/s00229-024-01584-w","url":null,"abstract":"<p>We generalize the work of Lindenstrauss and Venkatesh establishing Weyl’s Law for cusp forms from the spherical spectrum to arbitrary archimedean type. Weyl’s law for the spherical spectrum gives an asymptotic formula for the number of cusp forms that are bi-<span>(K_{infty })</span> invariant in terms of eigenvalue <i>T</i> of the Laplacian. We prove that an analogous asymptotic holds for cusp forms with archimedean type <span>(tau )</span>, where the main term is multiplied by <span>(dim {tau })</span>. While in the spherical case, the surjectivity of the Satake Map was used, in the more general case that is not available and we use Arthur’s Paley–Wiener theorem and multipliers.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"35 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141574616","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":"On $$textrm{H}-$$ trivial line bundles on toric DM stacks of dim $$ge 3$$","authors":"Lev Borisov, Chengxi Wang","doi":"10.1007/s00229-024-01583-x","DOIUrl":"https://doi.org/10.1007/s00229-024-01583-x","url":null,"abstract":"<p>We study line bundles on smooth toric Deligne-Mumford stacks <span>({mathbb {P}}_{mathbf {Sigma }})</span> of arbitrary dimension. We give a sufficient condition for when infinitely many line bundles on <span>({mathbb {P}}_{mathbf {Sigma }})</span> have trivial cohomology. In dimension three, this sufficient condition is also a necessary condition under the technical assumption that <span>(mathbf {Sigma })</span> has no more than one pair of collinear rays.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"5 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141574617","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":"Comparison between admissible and de Jong coverings in mixed characteristic","authors":"Sylvain Gaulhiac","doi":"10.1007/s00229-024-01578-8","DOIUrl":"https://doi.org/10.1007/s00229-024-01578-8","url":null,"abstract":"<p>Let <i>X</i> be an adic space locally of finite type over a complete non-archimedean field <i>k</i>, and denote <span>({textbf {Cov}}_{X}^{textrm{oc}})</span> (resp. <span>({textbf {Cov}}_{X}^{textrm{adm}})</span>) the category of étale coverings of <i>X</i> that are locally for the Berkovich overconvergent topology (resp. for the admissible topology) disjoint union of finite étale coverings. There is a natural inclusion <span>({textbf {Cov}}_{X}^{textrm{oc}}subseteq {textbf {Cov}}_{X}^{textrm{adm}})</span>. Whether or not this inclusion is strict is a question initially asked by de Jong. Some partial answers have been given in the recents works of Achinger, Lara and Youcis in the finite or equal characteristic 0 cases. The present note shows that this inclusion can be strict when <i>k</i> is of mixed characteristic (0, <i>p</i>) and <i>p</i>-closed. As a consequence, the natural morphism of Noohi groups <span>(pi _1^{mathrm {dJ, , adm}}(mathcal {C}, overline{x})rightarrow pi _1^{mathrm {dJ, ,oc}}(mathcal {C},overline{x}) )</span> is not an isomorphism in general.\u0000</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"18 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141574669","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":"The $${{,textrm{K},}}$$ -theory of the moduli stacks $${{mathcal {M}}}_2$$ and $$overline{{{mathcal {M}}}}_2$$","authors":"Dan Edidin, Zhengning Hu","doi":"10.1007/s00229-024-01581-z","DOIUrl":"https://doi.org/10.1007/s00229-024-01581-z","url":null,"abstract":"<p>We compute the integral Grothendieck rings of the moduli stacks, <span>({{mathcal {M}}}_2)</span>, <span>(overline{{{mathcal {M}}}}_2)</span> of smooth and stable curves of genus two respectively. We compute <span>({{,textrm{K},}}_0({{mathcal {M}}}_2))</span> by using the presentation of <span>({{mathcal {M}}}_2)</span> as a global quotient stack given by Vistoli (Invent Math 131(3):635–644, 1998). To compute the Grothendieck ring <span>({{,textrm{K},}}_0(overline{{{mathcal {M}}}}_2))</span> we decompose <span>(overline{{{mathcal {M}}}}_2)</span> as <span>(Delta _1)</span> and its complement <span>(overline{{{mathcal {M}}}}_2 setminus Delta _1)</span> and use their presentations as quotient stacks given by Larson (Algebr Geom 8 (3):286–318, 2021) to compute the Grothendieck rings. We show that they are torsion-free and this, together with the Riemann–Roch isomorphism allows us to ultimately give a presentation for the integral Grothendieck ring <span>({{,textrm{K},}}_0(overline{{{mathcal {M}}}}_2))</span>.\u0000</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"9 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547789","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":"On weaker notions for Kähler-Ricci solitons","authors":"Nefton Pali","doi":"10.1007/s00229-024-01577-9","DOIUrl":"https://doi.org/10.1007/s00229-024-01577-9","url":null,"abstract":"<p>We show that shrinking Kähler-Ricci solitons over a compact Kähler manifold are gradient shrinking Kähler-Ricci solitons. The proof relies on a remarkable identity on the kernels of a real and a complex elliptic operator proved in our solution of the variational stability problem for gradient shrinking Kähler-Ricci solitons in Pali (Complex Manifolds 3(1):41–144, 2016).</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"138 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510167","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-thin rank jumps for double elliptic K3 surfaces","authors":"Hector Pasten, Cecília Salgado","doi":"10.1007/s00229-024-01554-2","DOIUrl":"https://doi.org/10.1007/s00229-024-01554-2","url":null,"abstract":"<p>For an elliptic surface <span>(pi :Xrightarrow mathbb {P}^1)</span> defined over a number field <i>K</i>, a theorem of Silverman shows that for all but finitely many fibres above <i>K</i>-rational points, the resulting elliptic curve over <i>K</i> has Mordell-Weil rank at least as large as the rank of the group of sections of <span>(pi )</span>. When <i>X</i> is a <i>K</i>3 surface with two distinct elliptic fibrations, we show that the set of <i>K</i>-rational points of <span>(mathbb {P}^1)</span> for which this rank inequality is strict, is not a thin set, under certain hypothesis on the fibrations. Our results provide one of the first cases of this phenomenon beyond that of rational elliptic surfaces.</p>","PeriodicalId":49887,"journal":{"name":"Manuscripta Mathematica","volume":"25 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141525782","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}