Pub Date : 2024-04-05DOI: 10.1142/s0129167x24410076
Guillermo Gallego, Oscar García-Prada, M. S. Narasimhan
In this paper, we consider a generalization of the theory of Higgs bundles over a smooth complex projective curve in which the twisting of the Higgs field by the canonical bundle of the curve is replaced by a rank vector bundle. We define a Hitchin map and give a spectral correspondence. We also state a Hitchin–Kobayashi correspondence for a generalization of Hitchin’s equations to this situation. In a certain sense, this theory lies halfway between the theories of Higgs bundles on a curve and on a higher-dimensional variety.
{"title":"Higgs bundles twisted by a vector bundle","authors":"Guillermo Gallego, Oscar García-Prada, M. S. Narasimhan","doi":"10.1142/s0129167x24410076","DOIUrl":"https://doi.org/10.1142/s0129167x24410076","url":null,"abstract":"<p>In this paper, we consider a generalization of the theory of Higgs bundles over a smooth complex projective curve in which the twisting of the Higgs field by the canonical bundle of the curve is replaced by a rank <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><mn>2</mn></math></span><span></span> vector bundle. We define a Hitchin map and give a spectral correspondence. We also state a Hitchin–Kobayashi correspondence for a generalization of Hitchin’s equations to this situation. In a certain sense, this theory lies halfway between the theories of Higgs bundles on a curve and on a higher-dimensional variety.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601737","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}
Pub Date : 2024-04-05DOI: 10.1142/s0129167x24500216
Yuhei Suzuki
We extend theorems of Breuillard–Kalantar–Kennedy–Ozawa on unital reduced crossed products to the non-unital case under mild assumptions. As a result simplicity of -algebras is stable under taking reduced crossed products over discrete -simple groups, and a similar result for uniqueness of tracial weight. Interestingly, our analysis on tracial weights involves von Neumann algebra theory.
Our generalizations have two applications. The first is to locally compact groups. We establish stability results of (non-discrete) -simplicity and the unique trace property under discrete group extensions. The second is to the twisted crossed product. Thanks to the Packer–Raeburn theorem, our results lead to (generalizations of) the results of Bryder–Kennedy by a different method.
{"title":"Simplicity and tracial weights on non-unital reduced crossed products","authors":"Yuhei Suzuki","doi":"10.1142/s0129167x24500216","DOIUrl":"https://doi.org/10.1142/s0129167x24500216","url":null,"abstract":"<p>We extend theorems of Breuillard–Kalantar–Kennedy–Ozawa on unital reduced crossed products to the non-unital case under mild assumptions. As a result simplicity of <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>C</mi></mrow><mrow><mo stretchy=\"false\">∗</mo></mrow></msup></math></span><span></span>-algebras is stable under taking reduced crossed products over discrete <span><math altimg=\"eq-00002.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>C</mi></mrow><mrow><mo stretchy=\"false\">∗</mo></mrow></msup></math></span><span></span>-simple groups, and a similar result for uniqueness of tracial weight. Interestingly, our analysis on tracial weights involves von Neumann algebra theory.</p><p>Our generalizations have two applications. The first is to locally compact groups. We establish stability results of (non-discrete) <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>C</mi></mrow><mrow><mo stretchy=\"false\">∗</mo></mrow></msup></math></span><span></span>-simplicity and the unique trace property under discrete group extensions. The second is to the twisted crossed product. Thanks to the Packer–Raeburn theorem, our results lead to (generalizations of) the results of Bryder–Kennedy by a different method.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601738","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}
Pub Date : 2024-04-04DOI: 10.1142/s0129167x2441009x
Miguel González, Tamás Hausel
We define even very stable Higgs bundles and study the Hitchin map restricted to their upward flows. In the case, we classify the type examples, and find that they are governed by a root system formed by the roots of even height. We discuss how the spectrum of equivariant cohomology of real and quaternionic Grassmannians, -spheres and the real Cayley plane appear to describe the Hitchin map on even cominuscule upward flows. The even upward flows in question are the same as upward flows in Higgs bundle moduli spaces for quasi-split inner real forms. The latter spaces have been pioneered by Oscar García-Prada and his collaborators.
{"title":"Hitchin map on even very stable upward flows","authors":"Miguel González, Tamás Hausel","doi":"10.1142/s0129167x2441009x","DOIUrl":"https://doi.org/10.1142/s0129167x2441009x","url":null,"abstract":"<p>We define even very stable Higgs bundles and study the Hitchin map restricted to their upward flows. In the <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><msub><mrow><mstyle><mtext mathvariant=\"normal\">GL</mtext></mstyle></mrow><mrow><mi>n</mi></mrow></msub></math></span><span></span> case, we classify the type <span><math altimg=\"eq-00002.gif\" display=\"inline\" overflow=\"scroll\"><mo stretchy=\"false\">(</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>1</mn><mo stretchy=\"false\">)</mo></math></span><span></span> examples, and find that they are governed by a root system formed by the roots of even height. We discuss how the spectrum of equivariant cohomology of real and quaternionic Grassmannians, <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><mn>4</mn><mi>n</mi></math></span><span></span>-spheres and the real Cayley plane appear to describe the Hitchin map on even cominuscule upward flows. The even upward flows in question are the same as upward flows in Higgs bundle moduli spaces for quasi-split inner real forms. The latter spaces have been pioneered by Oscar García-Prada and his collaborators.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601872","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}
Pub Date : 2024-04-04DOI: 10.1142/s0129167x24410027
Indranil Biswas, Jacques Hurtubise
We consider for structure groups a densely defined toric structure on the moduli space of framed parabolic sheaves on a three-punctured sphere, which degenerates to an actual toric structure. In combination with previous degeneration results, these extend to similar moduli for arbitrary Riemann surfaces.
{"title":"Framed parabolic sheaves on a trinion","authors":"Indranil Biswas, Jacques Hurtubise","doi":"10.1142/s0129167x24410027","DOIUrl":"https://doi.org/10.1142/s0129167x24410027","url":null,"abstract":"<p>We consider for structure groups <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><mstyle><mtext mathvariant=\"normal\">SU</mtext></mstyle><mo stretchy=\"false\">(</mo><mi>n</mi><mo stretchy=\"false\">)</mo><mspace width=\".17em\"></mspace><mo>⊂</mo><mspace width=\".17em\"></mspace><mstyle><mtext mathvariant=\"normal\">SL</mtext></mstyle><mo stretchy=\"false\">(</mo><mi>n</mi><mo>,</mo><mi>ℂ</mi><mo stretchy=\"false\">)</mo></math></span><span></span> a densely defined toric structure on the moduli space of framed parabolic sheaves on a three-punctured sphere, which degenerates to an actual toric structure. In combination with previous degeneration results, these extend to similar moduli for arbitrary Riemann surfaces.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601913","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}
Pub Date : 2024-04-04DOI: 10.1142/s0129167x24410052
Simon Donaldson, Fabian Lehmann
The focus of this paper is on a volume form defined on a pseudoconvex hypersurface in a complex Calabi–Yau manifold (that is, a complex -manifold with a nowhere-vanishing holomorphic -form). We begin by defining this volume form and observing that it can be viewed as a generalization of the affine-invariant volume form on a convex hypersurface in . We compute the first variation, which leads to a similar generalization of the affine mean curvature. In Sec. 2, we investigate the constrained variational problem, for pseudoconvex hypersurfaces bounding compact domains . That is, we study critical points of the volume functional where the ordinary volume is fixed. The critical points are analogous to constant mean curvature submanifolds. We find that Sasaki–Einstein hypersurfaces satisfy the condition, and in particular the standard sphere does. The main work in the paper comes in Sec. 3 where we compute the second variation about the sphere. We find that it is negative in “most” directions but non-negative in directions corresponding to deformations of by holomorphic diffeomorphisms. We are led to conjecture a “minimax” characterization of the sphere. We also discuss connections with the affine geometry case and with Kähler–Einstein geometry. Our original motivation for investigating these matters came from the case
本文的重点是在复 Calabi-Yau 流形(即具有无处消失全形 n 形式的复 n 流形)中的伪凸超曲面 M 上定义的一种体积形式。我们首先定义这种体量形式,并指出它可以看作是 Rn 中凸超曲面上仿射不变体量形式的广义化。我们计算了第一个变化,这导致了仿射平均曲率的类似广义化。在第 2 节中,我们研究了以紧凑域 Ω⊂Z 为边界的伪凸超曲面 M 的约束变分问题。也就是说,我们研究的是普通体积 V(Ω) 固定的体积函数 A(M) 的临界点。临界点类似于恒定平均曲率子曲面。我们发现佐佐木-爱因斯坦超曲面满足条件,尤其是标准球 S2n-1⊂Cn 满足条件。本文的主要工作在第 3 节,我们计算了球面的第二次变化。我们发现它在 "大多数 "方向上都是负值,但在全形差分变形对应的 S2n-1 变形方向上却不是负值。我们由此猜想出球面的 "最小 "特征。我们还讨论了与仿射几何和凯勒-爱因斯坦几何的联系。我们研究这些问题的最初动机来自 n=3 的情况和我们之前论文 [S. Donaldson and F. Leinstein] 中研究的嵌入问题。Donaldson and F. Lehmann, Closed 3-forms in five dimensions and embedding problems, preprint (2022), arXiv:2210.16208].这种情况有一些特殊之处。在第 4 节中,我们将回顾这一点,并从 M 上精确 3-forms 的交映结构和 M 的差分作用的矩映射的角度发展一些理论。
{"title":"Volume functionals on pseudoconvex hypersurfaces","authors":"Simon Donaldson, Fabian Lehmann","doi":"10.1142/s0129167x24410052","DOIUrl":"https://doi.org/10.1142/s0129167x24410052","url":null,"abstract":"<p>The focus of this paper is on a volume form defined on a pseudoconvex hypersurface <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><mi>M</mi></math></span><span></span> in a complex Calabi–Yau manifold (that is, a complex <span><math altimg=\"eq-00002.gif\" display=\"inline\" overflow=\"scroll\"><mi>n</mi></math></span><span></span>-manifold with a nowhere-vanishing holomorphic <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><mi>n</mi></math></span><span></span>-form). We begin by defining this volume form and observing that it can be viewed as a generalization of the affine-invariant volume form on a convex hypersurface in <span><math altimg=\"eq-00004.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mstyle><mtext mathvariant=\"normal\">R</mtext></mstyle></mrow><mrow><mi>n</mi></mrow></msup></math></span><span></span>. We compute the first variation, which leads to a similar generalization of the affine mean curvature. In Sec. 2, we investigate the constrained variational problem, for pseudoconvex hypersurfaces <span><math altimg=\"eq-00005.gif\" display=\"inline\" overflow=\"scroll\"><mi>M</mi></math></span><span></span> bounding compact domains <span><math altimg=\"eq-00006.gif\" display=\"inline\" overflow=\"scroll\"><mi mathvariant=\"normal\">Ω</mi><mo>⊂</mo><mi>Z</mi></math></span><span></span>. That is, we study critical points of the volume functional <span><math altimg=\"eq-00007.gif\" display=\"inline\" overflow=\"scroll\"><mi>A</mi><mo stretchy=\"false\">(</mo><mi>M</mi><mo stretchy=\"false\">)</mo></math></span><span></span> where the ordinary volume <span><math altimg=\"eq-00008.gif\" display=\"inline\" overflow=\"scroll\"><mi>V</mi><mo stretchy=\"false\">(</mo><mi mathvariant=\"normal\">Ω</mi><mo stretchy=\"false\">)</mo></math></span><span></span> is fixed. The critical points are analogous to constant mean curvature submanifolds. We find that Sasaki–Einstein hypersurfaces satisfy the condition, and in particular the standard sphere <span><math altimg=\"eq-00009.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn><mi>n</mi><mo stretchy=\"false\">−</mo><mn>1</mn></mrow></msup><mo>⊂</mo><msup><mrow><mstyle><mtext mathvariant=\"normal\">C</mtext></mstyle></mrow><mrow><mi>n</mi></mrow></msup></math></span><span></span> does. The main work in the paper comes in Sec. 3 where we compute the second variation about the sphere. We find that it is negative in “most” directions but non-negative in directions corresponding to deformations of <span><math altimg=\"eq-00010.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn><mi>n</mi><mo stretchy=\"false\">−</mo><mn>1</mn></mrow></msup></math></span><span></span> by holomorphic diffeomorphisms. We are led to conjecture a “minimax” characterization of the sphere. We also discuss connections with the affine geometry case and with Kähler–Einstein geometry. Our original motivation for investigating these matters came from the case <span><m","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601730","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}
Pub Date : 2024-04-03DOI: 10.1142/s0129167x24500277
Pierre Bieliavsky, Victor Gayral, Sergey Neshveyev, Lars Tuset
Given an extension of locally compact groups, with abelian, and a compatible essentially bijective -cocycle , we define a dual unitary -cocycle on and show that the associated deformation of is a cocycle bicrossed product defined by a matched pair of subgroups of . We also discuss an interpretation of our construction from the point of view of Kac cohomology for matched pairs. Our setup generalizes that of Etingof and Gelaki for finite groups and its extension due to Ben David and Ginosar, as well as our earlier work on locally compact groups satisfying the dual orbit condition. In particular, we get a locally compact quantum group from every involutive nondegenerate set-theoretical solution of the Yang–Baxter equation, or more generally, from every brace structure. On the technical side, the key new points are constructions of an irreducible projective representation of on and a unitary quantization map of Kohn–Nirenberg type.
给定局部紧密群的扩展 0→V→G→Q→1,其中 V 是无性的,以及一个相容的本质上双射的 1 循环 η:Q→V̂,我们定义了 G 上的对偶单元 2 循环,并证明Ĝ 的相关变形是由 Q⋉V ̂ 的一对匹配子群定义的循环双交积。我们还讨论了从匹配对的 Kac 同调的角度对我们的构造的解释。我们的设置概括了 Etingof 和 Gelaki 对有限群的设置、Ben David 和 Ginosar 对其的扩展,以及我们早期对满足对偶轨道条件的局部紧凑群的研究。特别是,我们从杨-巴克斯特方程的每一个渐开非enerate集合理论解,或者更广义地说,从每一个支撑结构,都可以得到一个局部紧凑的量子群。在技术方面,新的关键点在于构建了 G 在 L2(Q) 上的不可还原投影表示和 Kohn-Nirenberg 类型的单元量子化映射 L2(G)→HS(L2(Q))。
{"title":"Quantization of locally compact groups associated with essentially bijective 1-cocycles","authors":"Pierre Bieliavsky, Victor Gayral, Sergey Neshveyev, Lars Tuset","doi":"10.1142/s0129167x24500277","DOIUrl":"https://doi.org/10.1142/s0129167x24500277","url":null,"abstract":"<p>Given an extension <span><math altimg=\"eq-00002.gif\" display=\"inline\" overflow=\"scroll\"><mn>0</mn><mo>→</mo><mi>V</mi><mo>→</mo><mi>G</mi><mo>→</mo><mi>Q</mi><mo>→</mo><mn>1</mn></math></span><span></span> of locally compact groups, with <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><mi>V</mi></math></span><span></span> abelian, and a compatible essentially bijective <span><math altimg=\"eq-00004.gif\" display=\"inline\" overflow=\"scroll\"><mn>1</mn></math></span><span></span>-cocycle <span><math altimg=\"eq-00005.gif\" display=\"inline\" overflow=\"scroll\"><mi>η</mi><mo>:</mo><mi>Q</mi><mo>→</mo><mover accent=\"true\"><mrow><mi>V</mi></mrow><mo>̂</mo></mover></math></span><span></span>, we define a dual unitary <span><math altimg=\"eq-00006.gif\" display=\"inline\" overflow=\"scroll\"><mn>2</mn></math></span><span></span>-cocycle on <span><math altimg=\"eq-00007.gif\" display=\"inline\" overflow=\"scroll\"><mi>G</mi></math></span><span></span> and show that the associated deformation of <span><math altimg=\"eq-00008.gif\" display=\"inline\" overflow=\"scroll\"><mi>Ĝ</mi></math></span><span></span> is a cocycle bicrossed product defined by a matched pair of subgroups of <span><math altimg=\"eq-00009.gif\" display=\"inline\" overflow=\"scroll\"><mi>Q</mi><mo stretchy=\"false\">⋉</mo><mover accent=\"true\"><mrow><mi>V</mi></mrow><mo>̂</mo></mover></math></span><span></span>. We also discuss an interpretation of our construction from the point of view of Kac cohomology for matched pairs. Our setup generalizes that of Etingof and Gelaki for finite groups and its extension due to Ben David and Ginosar, as well as our earlier work on locally compact groups satisfying the dual orbit condition. In particular, we get a locally compact quantum group from every involutive nondegenerate set-theoretical solution of the Yang–Baxter equation, or more generally, from every brace structure. On the technical side, the key new points are constructions of an irreducible projective representation of <span><math altimg=\"eq-00010.gif\" display=\"inline\" overflow=\"scroll\"><mi>G</mi></math></span><span></span> on <span><math altimg=\"eq-00011.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo stretchy=\"false\">(</mo><mi>Q</mi><mo stretchy=\"false\">)</mo></math></span><span></span> and a unitary quantization map <span><math altimg=\"eq-00012.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo stretchy=\"false\">(</mo><mi>G</mi><mo stretchy=\"false\">)</mo><mo>→</mo><mstyle><mtext mathvariant=\"normal\">HS</mtext></mstyle><mo stretchy=\"false\">(</mo><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo stretchy=\"false\">(</mo><mi>Q</mi><mo stretchy=\"false\">)</mo><mo stretchy=\"false\">)</mo></math></span><span></span> of Kohn–Nirenberg type.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601722","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}
Pub Date : 2024-04-03DOI: 10.1142/s0129167x24500241
Arnulfo Miguel Rodríguez Peña
The number of singularities, counted with multiplicity, of a generic codimension one holomorphic distribution on a compact toric orbifold is determined. As a consequence, we provide a classification for regular distributions on rational normal scrolls and weighted projective spaces. Additionally, under specific conditions, we prove that the singular set of a codimension one holomorphic foliation on a compact toric orbifold admits at least one irreducible component of codimension two, and we also present a Darboux–Jouanolou type integrability theorem for codimension one holomorphic foliations. Our results are exemplified through various illustrative examples.
{"title":"On codimension one holomorphic distributions on compact toric orbifolds","authors":"Arnulfo Miguel Rodríguez Peña","doi":"10.1142/s0129167x24500241","DOIUrl":"https://doi.org/10.1142/s0129167x24500241","url":null,"abstract":"<p>The number of singularities, counted with multiplicity, of a generic codimension one holomorphic distribution on a compact toric orbifold is determined. As a consequence, we provide a classification for regular distributions on rational normal scrolls and weighted projective spaces. Additionally, under specific conditions, we prove that the singular set of a codimension one holomorphic foliation on a compact toric orbifold admits at least one irreducible component of codimension two, and we also present a Darboux–Jouanolou type integrability theorem for codimension one holomorphic foliations. Our results are exemplified through various illustrative examples.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140601731","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}
Pub Date : 2024-03-28DOI: 10.1142/s0129167x24500253
Yongming Wen, Yanyan Han, Xianming Hou
This paper obtains weak-type estimates, limiting weak-type behaviors for variation operators associated with functions. Besides, we give a new characterization of Hardy space via the boundedness of variation operators associated with functions.
{"title":"Endpoint estimates of variation and oscillation operators associated with Zλ functions","authors":"Yongming Wen, Yanyan Han, Xianming Hou","doi":"10.1142/s0129167x24500253","DOIUrl":"https://doi.org/10.1142/s0129167x24500253","url":null,"abstract":"<p>This paper obtains weak-type estimates, limiting weak-type behaviors for variation operators associated with <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>Z</mi></mrow><mrow><mi>λ</mi></mrow></msup></math></span><span></span> functions. Besides, we give a new characterization of Hardy space via the boundedness of variation operators associated with <span><math altimg=\"eq-00004.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>Z</mi></mrow><mrow><mi>λ</mi></mrow></msup></math></span><span></span> functions.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314817","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}
Pub Date : 2024-03-27DOI: 10.1142/s0129167x24410131
Carlos T. Simpson
Let be a smooth quasi-projective curve. We previously constructed a Deligne–Hitchin moduli space with Hecke gauge groupoid for connections of rank . We extend this construction to the case of any rank , although still keeping a genericity hypothesis. The formal neighborhood of a preferred section corresponding to a tame harmonic bundle is governed by a mixed twistor structure.
{"title":"Twistor space for local systems on an open curve","authors":"Carlos T. Simpson","doi":"10.1142/s0129167x24410131","DOIUrl":"https://doi.org/10.1142/s0129167x24410131","url":null,"abstract":"<p>Let <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><mi>X</mi><mo>=</mo><mover accent=\"false\"><mrow><mi>X</mi></mrow><mo accent=\"true\">¯</mo></mover><mo stretchy=\"false\">−</mo><mi>D</mi></math></span><span></span> be a smooth quasi-projective curve. We previously constructed a Deligne–Hitchin moduli space with Hecke gauge groupoid for connections of rank <span><math altimg=\"eq-00002.gif\" display=\"inline\" overflow=\"scroll\"><mn>2</mn></math></span><span></span>. We extend this construction to the case of any rank <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><mi>r</mi></math></span><span></span>, although still keeping a genericity hypothesis. The formal neighborhood of a preferred section corresponding to a tame harmonic bundle is governed by a mixed twistor structure.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314910","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}
Pub Date : 2024-03-20DOI: 10.1142/s0129167x24410040
Andrew Dancer, Frances Kirwan, Johan Martens
We give a survey of the implosion construction, extending some of its aspects relating to hypertoric geometry from type to a general reductive group, and interpret it in the context of the Moore–Tachikawa category. We use these ideas to discuss how the contraction construction in symplectic geometry can be generalized to the hyperkähler or complex symplectic situation.
我们考察了内爆构造,将其与高折射几何有关的某些方面从 A 型扩展到一般还原群,并在摩尔-立川范畴的背景下对其进行了解释。我们利用这些观点来讨论如何将交点几何中的内卷构造推广到超交点或复交点情形中。
{"title":"Implosion, contraction and Moore–Tachikawa","authors":"Andrew Dancer, Frances Kirwan, Johan Martens","doi":"10.1142/s0129167x24410040","DOIUrl":"https://doi.org/10.1142/s0129167x24410040","url":null,"abstract":"<p>We give a survey of the implosion construction, extending some of its aspects relating to hypertoric geometry from type <span><math altimg=\"eq-00001.gif\" display=\"inline\" overflow=\"scroll\"><mi>A</mi></math></span><span></span> to a general reductive group, and interpret it in the context of the Moore–Tachikawa category. We use these ideas to discuss how the contraction construction in symplectic geometry can be generalized to the hyperkähler or complex symplectic situation.</p>","PeriodicalId":54951,"journal":{"name":"International Journal of Mathematics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140200625","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}