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$$C^{1,\alpha }$$ -regularity for p-harmonic functions on SU(3) and semi-simple Lie groups Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2024-03-18 Chengwei Yu
In this paper, when \(1
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Biconservative surfaces with constant mean curvature in lorentzian space forms Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2024-01-29 Aykut Kayhan, Nurettin Cenk Turgay
In this paper, we consider biconservative and biharmonic isometric immersions into the 4-dimensional Lorentzian space form \({\mathbb {L}}^4(\delta )\) with constant sectional curvature \(\delta \). We obtain some local classifications of biconservative CMC surfaces in \({\mathbb {L}}^4(\delta )\). Further, we get complete classification of biharmonic CMC surfaces in the de Sitter 4-space. We also
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Towards generic base-point-freeness for hyperkähler manifolds of generalized Kummer type Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-11-16 Mauro Varesco
We study base-point-freeness for big and nef line bundles on hyperkähler manifolds of generalized Kummer type: For \(n\in \{2,3,4\}\), we show that, generically in all but a finite number of irreducible components of the moduli space of polarized \(\textrm{Kum}^n\)-type varieties, the polarization is base-point-free. We also prove generic base-point-freeness in the moduli space in all dimensions if
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Correction to: Isotropicity of surfaces in Lorentzian 4-manifolds with zero mean curvature vector Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-11-13 Naoya Ando
Abstract In this paper, we see that the hypersurfaces \(\mathcal {L}_{\pm }\) in Ando (Abh Math Semin Univ Hambg 92:105–123, 2022, Proposition 1) are neutral but not flat. Nonetheless, we find parallel almost complex structures \(\mathcal {I}_{\pm }\) suitable for Ando (Abh Math Semin Univ Hambg 92:105–123, 2022, Theorem 1) and parallel almost paracomplex structures \(\mathcal {J}_{\pm }\) suitable
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An example of Tateno disproving conjectures of Bonato–Tardif, Thomasse, and Tyomkyn Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-11-01 Davoud Abdi Kalow, Claude Laflamme, Atsushi Tateno, Robert Woodrow
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Lines on p-adic and real cubic surfaces Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-09-16 Rida Ait El Manssour, Yassine El Maazouz, Enis Kaya, Kemal Rose
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On curves on Hirzebruch surfaces Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-06-08 Gerriet Martens
We call a smooth irreducible projective curve a Castelnuovo curve if it admits a birational map into the projective r-space such that the image curve has degree at least 2r+1 and the maximum possible geometric genus (which one can calculate by a classical formula due to Castelnuovo). It is well known that a Castelnuovo curve must lie on a Hirzebruch surface (rational ruled surface). Conversely, making
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An equivalent to the Riemann hypothesis in the Selberg class Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-05-17 Ramūnas Garunkštis, Jokūbas Putrius
In 2020 S. M. Gonek, S. W. Graham and Y. Lee formulated the Lindelöf hypothesis for prime numbers and proved that it is equivalent to the Riemann Hypothesis. In this note we show that their result holds in the Selberg class of L-functions.
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An Unexpected Cyclic Symmetry of $$I{\mathfrak u}_n$$ Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-03-16 Dror Bar-Natan, Roland van der Veen
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Analytic semi-universal deformations in logarithmic complex geometry Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-02-24 Raffaele Caputo
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A Brunn–Minkowski type inequality for extended symplectic capacities of convex domains and length estimate for a class of billiard trajectories Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-02-23 Rongrong Jin, Guangcun Lu
In this paper, we firstly generalize the Brunn–Minkowski type inequality for Ekeland–Hofer–Zehnder symplectic capacity of bounded convex domains established by Artstein-Avidan–Ostrover in 2008 to extended symplectic capacities of bounded convex domains constructed by authors based on a class of Hamiltonian non-periodic boundary value problems recently. Then we introduce a class of non-periodic billiards
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Picard schemes of noncommutative bielliptic surfaces Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2023-02-14 Fabian Reede
We study the nontrivial elements in the Brauer group of a bielliptic surface and show that they can be realized as Azumaya algebras with a simple structure at the generic point of the surface. We go on to study some properties of the noncommutative Picard scheme associated to such an Azumaya algebra.
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Existence and uniqueness of renormalized solutions for initial boundary value parabolic problems with possibly very singular right-hand side Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-12-13 M. Abdellaoui, H. Redwane
We study the existence and uniqueness of renormalized solutions for initial boundary value problems of the type $$\begin{aligned} \left( {\mathcal {P}}_{b}^{1}\right) \quad \left\{ \begin{aligned} u_{t}-\text {div}(a(t,x,\nabla u))=H(u)\mu \text { in }Q:=(0,T)\times \Omega ,\\ u(0,x)=u_{0}(x)\text { in }\Omega ,\ u(t,x)=0\text { on }(0,T)\times \partial \Omega , \end{aligned}\right. \end{aligned}$$
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A tree-of-tangles theorem for infinite tangles Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-11-29 Ann-Kathrin Elm, Jan Kurkofka
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$$G_2$$ -structures on flat solvmanifolds Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-11-11 Alejandro Tolcachier
In this article we study the relation between flat solvmanifolds and \(G_2\)-geometry. First, we give a classification of 7-dimensional flat splittable solvmanifolds using the classification of finite subgroups of \(\mathsf{GL}(n,\mathbb {Z})\) for \(n=5\) and \(n=6\). Then, we look for closed, coclosed and divergence-free \(G_2\)-structures compatible with the flat metric on them. In particular, we
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Local positivity and effective Diophantine approximation Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-11-08 Matthias Nickel
In this paper we present a new approach to prove effective results in Diophantine approximation. This approach involves measures of local positivity of divisors combined with Faltings’s version of Siegel’s lemma instead of a zero estimate such as Dyson’s lemma. We then use it to prove an effective theorem on the simultaneous approximation of two algebraic numbers satisfying an algebraic equation with
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On linear stability and syzygy stability Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-05-30 Abel Castorena, Ernesto C. Mistretta, Hugo Torres-López
In previous works, the authors investigated the relationships between linear stability of a generated linear series |V| on a curve C, and slope stability of the syzygy vector bundle \(M_{V,L} := \ker (V \otimes \mathcal {O}_C \rightarrow L)\). In particular, the second named author and L. Stoppino conjecture that, for a complete linear system |L|, linear (semi)stability is equivalent to slope (semi)stability
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Triangular lat-igusa-todorov algebras Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-05-24 José Armando Vivero
In 2021 the authors D. Bravo, M. Lanzilotta, O. Mendoza and J. Vivero gave a generalization of the concept of Igusa-Todorov algebra and proved that those algebras, named Lat-Igusa-Todorov (LIT for short), satisfy the finitistic dimension conjecture. In this paper we explore the scope of that generalization and give conditions for a triangular matrix algebra to be LIT in terms of the algebras and the
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Derivatives of Eisenstein series of weight 2 and intersections of modular correspondences Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-04-27 Sungmun Cho, Shunsuke Yamana, Takuya Yamauchi
We give a formula for certain values and derivatives of Siegel series and use them to compute Fourier coefficients of derivatives of the Siegel Eisenstein series of weight \(\frac{g}{2}\) and genus g. When \(g=4\), the Fourier coefficient is approximated by a certain Fourier coefficient of the central derivative of the Siegel Eisenstein series of weight 2 and genus 3, which is related to the intersection
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Fourier coefficients of the Siegel Eisenstein series of degree 2 with odd prime level, corresponding to the middle cusp Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-01-18 Keiichi Gunji
Let p be an odd prime. In this paper we compute the Fourier coefficients of the Siegel Eisenstein series of degree 2, level p with the trivial or the quadratic character, associated to a certain cusp. For that we need to define the p-factor of the special type of Siegel series with character.
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Isotropicity of surfaces in Lorentzian 4-manifolds with zero mean curvature vector Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-01-03 Naoya Ando
We already have the concept of isotropicity of a minimal surface in a Riemannian 4-manifold and a space-like or time-like surface in a neutral 4-manifold with zero mean curvature vector. In this paper, based on the understanding of it, we define and study isotropicity of a space-like or time-like surface in a Lorentzian 4-manifold N with zero mean curvature vector. If the surface is space-like, then
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Set recognition of decomposable graphs and steps towards their reconstruction Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2022-01-03 Bernd S. W. Schröder
It is proved that decomposable graphs are set recognizable and that the index graph of the canonical decomposition as well as the graphs induced on the maximal autonomous sets of vertices are set reconstructible. From these results, we obtain set reconstructibility for many decomposable graphs as well as a concise description of the decomposable graphs for which set reconstruction remains an open problem
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A short note on sign changes and non-vanishing of Fourier coefficients of half-integral weight cusp forms Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-12-14 Winfried Kohnen
We study sign changes and non-vanishing of a certain double sequence of Fourier coefficients of cusp forms of half-integral weight.
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Constant cycle and co-isotropic subvarieties in a Mukai system Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-11-10 Hellmann, Isabell
Combining theorems of Voisin and Marian, Shen, Yin and Zhao, we compute the dimensions of the orbits under rational equivalence in the Mukai system of rank two and genus two. We produce several examples of algebraically coisotropic and constant cycle subvarieties.
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A model for random chain complexes Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-11-09 Michael J. Catanzaro, Matthew J. Zabka
We introduce a model for random chain complexes over a finite field. The randomness in our complex comes from choosing the entries in the matrices that represent the boundary maps uniformly over \(\mathbb {F}_q\), conditioned on ensuring that the composition of consecutive boundary maps is the zero map. We then investigate the combinatorial and homological properties of this random chain complex.
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On a non-local area-preserving curvature flow in the plane Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-09-30 Sun, Zezhen
In this paper, we consider a kind of area-preserving flow for closed convex planar curves which will decrease the length of the evolving curve and make the evolving curve more and more circular during the evolution process. And the final shape of the evolving curve will be a circle as time \(t\rightarrow +\infty \).
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The characterization of aCM line bundles on quintic hypersurfaces in $$\mathbb {P}^3$$ P 3 Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-09-28 Watanabe, Kenta
Let X be a smooth quintic hypersurface in \(\mathbb {P}^3\), let C be a smooth hyperplane section of X, and let \(H=\mathcal {O}_X(C)\). In this paper, we give a necessary and sufficient condition for the line bundle given by a non-zero effective divisor on X to be initialized and aCM with respect to H.
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Correction to: A counting invariant for maps into spheres and for zero loci of sections of vector bundles Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-09-14 Panagiotis Konstantis
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Dirichlet series expansions of p-adic L-functions Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-08-30 Knospe, Heiko, Washington, Lawrence C.
We study p-adic L-functions \(L_p(s,\chi )\) for Dirichlet characters \(\chi \). We show that \(L_p(s,\chi )\) has a Dirichlet series expansion for each regularization parameter c that is prime to p and the conductor of \(\chi \). The expansion is proved by transforming a known formula for p-adic L-functions and by controlling the limiting behavior. A finite number of Euler factors can be factored
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Topological mirror symmetry for rank two character varieties of surface groups Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-08-21 Mauri, Mirko
The moduli spaces of flat \({\text{SL}}_2\)- and \({\text{PGL}}_2\)-connections are known to be singular SYZ-mirror partners. We establish the equality of Hodge numbers of their intersection (stringy) cohomology. In rank two, this answers a question raised by Tamás Hausel in Remark 3.30 of “Global topology of the Hitchin system”.
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Two graded rings of Hermitian modular forms Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-08-12 Williams, Brandon
We give generators and relations for the graded rings of Hermitian modular forms of degree two over the rings of integers in \({\mathbb {Q}}(\sqrt{-7})\) and \({\mathbb {Q}}(\sqrt{-11})\). In both cases we prove that the subrings of symmetric modular forms are generated by Maass lifts. The computation uses a reduction process against Borcherds products which also leads to a dimension formula for the
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A-hypergeometric series and a p-adic refinement of the Hasse-Witt matrix Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-08-09 Adolphson, Alan, Sperber, Steven
We identify the p-adic unit roots of the zeta function of a projective hypersurface over a finite field of characteristic p as the eigenvalues of a product of special values of a certain matrix of p-adic series. That matrix is a product \(F(\varLambda ^p)^{-1}F(\varLambda )\), where the entries in the matrix \(F(\varLambda )\) are A-hypergeometric series with integral coefficients and \(F(\varLambda
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On functorial (co)localization of algebras and modules over operads Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-07-22 Javier J. Gutiérrez,Oliver Röndigs,Markus Spitzweck,Paul Arne Østvær
AbstractMotivated by calculations of motivic homotopy groups, we give widely attained conditions under which operadic algebras and modules thereof are preserved under (co)localization functors.
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On the growth and zeros of polynomials attached to arithmetic functions Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-06-14 Bernhard Heim, Markus Neuhauser
In this paper we investigate growth properties and the zero distribution of polynomials attached to arithmetic functions g and h, where g is normalized, of moderate growth, and \(0
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A geometric splitting theorem for actions of semisimple Lie groups Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-06-07 José Rosales-Ortega
Let M be a compact connected smooth pseudo-Riemannian manifold that admits a topologically transitive G-action by isometries, where \(G = G_1 \ldots G_l\) is a connected semisimple Lie group without compact factors whose Lie algebra is \({\mathfrak {g}}= {\mathfrak {g}}_1 \oplus {\mathfrak {g}}_2 \oplus \cdots \oplus {\mathfrak {g}}_l\). If \(m_0,n_0,n_0^i\) are the dimensions of the maximal lightlike
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Correction to: Variants of Hörmander’s theorem on q-convex manifolds by a technique of infinitely many weights Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-05-25 Takeo Ohsawa
A correction to this paper has been published: https://doi.org/10.1007/s12188-021-00239-x
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Algebraic realization for projective special linear actions Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-05-17 Karl Heinz Dovermann, Vincent Giambalvo
Suppose \(q=p^r\), where p is a prime congruent to 3 or 5 modulo 8 and r is odd or \(q = 2^r\) for any r. Then every closed smooth \({\text {PSL}}(2,q)\) manifold has a strongly algebraic model.
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Variants of Hörmander’s theorem on q -convex manifolds by a technique of infinitely many weights Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-04-26 Takeo Ohsawa
By introducing a new approximation technique in the \(L^2\) theory of the \(\bar{\partial }\)-operator, Hörmander’s \(L^2\) variant of Andreotti-Grauert’s finiteness theorem is extended and refined on q-convex manifolds and weakly 1-complete manifolds. As an application, a question on the \(L^2\) cohomology suggested by a theory of Ueda (Tohoku Math J (2) 31(1):81–90, 1979), Ueda (J Math Kyoto Univ
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Correction to: Seifert fibrations of lens spaces Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-04-21 Hansjörg Geiges, Christian Lange
We classify the Seifert fibrations of lens spaces where the base orbifold is non-orientable. This is an addendum to our earlier paper ‘Seifert fibrations of lens spaces’. We correct Lemma 4.1 of that paper and fill the gap in the classification that resulted from the erroneous lemma.
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Infinite order linear differential equation satisfied by p -adic Hurwitz-type Euler zeta functions Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-03-17 Su Hu, Min-Soo Kim
In 1900, at the international congress of mathematicians, Hilbert claimed that the Riemann zeta function \(\zeta (s)\) is not the solution of any algebraic ordinary differential equations on its region of analyticity. In 2015, Van Gorder (J Number Theory 147:778–788, 2015) considered the question of whether \(\zeta (s)\) satisfies a non-algebraic differential equation and showed that it formally satisfies
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Automorphic forms for some even unimodular lattices Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-02-20 Neil Dummigan, Dan Fretwell
We look at genera of even unimodular lattices of rank 12 over the ring of integers of \({{\mathbb {Q}}}(\sqrt{5})\) and of rank 8 over the ring of integers of \({{\mathbb {Q}}}(\sqrt{3})\), using Kneser neighbours to diagonalise spaces of scalar-valued algebraic modular forms. We conjecture most of the global Arthur parameters, and prove several of them using theta series, in the manner of Ikeda and
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On the $$\Delta $$ Δ -property for complex space forms Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-02-17 Roberto Mossa
Inspired by the work of Lu and Tian (Duke Math J 125:351--387, 2004), Loi et al. address in (Abh Math Semin Univ Hambg 90: 99-109, 2020) the problem of studying those Kähler manifolds satisfying the \(\Delta \)-property, i.e. such that on a neighborhood of each of its points the k-th power of the Kähler Laplacian is a polynomial function of the complex Euclidean Laplacian, for all positive integer
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Symmetric Tornheim double zeta functions Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-02-09 Takashi Nakamura
Let \(s,t,u \in {{\mathbb {C}}}\) and T(s, t, u) be the Tornheim double zeta function. In this paper, we investigate some properties of symmetric Tornheim double zeta functions which can be regarded as a desingularization of the Tornheim double zeta function. As a corollary, we give explicit evaluation formulas or rapidly convergent series representations for T(s, t, u) in terms of series of the gamma
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The cotangent complex and Thom spectra Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-01-27 Nima Rasekh, Bruno Stonek
The cotangent complex of a map of commutative rings is a central object in deformation theory. Since the 1990s, it has been generalized to the homotopical setting of \(E_\infty \)-ring spectra in various ways. In this work we first establish, in the context of \(\infty \)-categories and using Goodwillie’s calculus of functors, that various definitions of the cotangent complex of a map of \(E_\infty
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Arithmetic properties of 3-regular partitions with distinct odd parts Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2021-01-17 V. S. Veena, S. N. Fathima
Let $$pod_3(n)$$ p o d 3 ( n ) denote the number of 3-regular partitions of n with distinct odd parts (and even parts are unrestricted). In this article, we prove an infinite family of congruences for $$pod_3(n)$$ p o d 3 ( n ) using the theory of Hecke eigenforms. We also study the divisibility properties of $$pod_3(n)$$ p o d 3 ( n ) using arithmetic properties of modular forms.
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Clifford systems, Clifford structures, and their canonical differential forms Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-12-08 Kai Brynne M. Boydon, Paolo Piccinni
A comparison among different constructions of the quaternionic $4$-form $\Phi_{Sp(2)Sp(1)}$ and of the Cayley calibration $\Phi_{Spin(7)}$ shows that one can start for them from the same collections of "Kahler 2-forms", entering in dimension 8 both in quaternion Kahler and in $Spin(7)$ geometry. This comparison relates with the notions of even Clifford structure and of Clifford system. Going to dimension
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A counting invariant for maps into spheres and for zero loci of sections of vector bundles Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-11-27 Panagiotis Konstantis
The set of unrestricted homotopy classes $[M,S^n]$ where $M$ is a closed and connected spin $(n+1)$-manifold is called the $n$-th cohomotopy group $\pi^n(M)$ of $M$. Moreover it is known that $\pi^n(M) = H^n(M;\mathbb Z) \oplus \mathbb Z_2$ by methods from homotopy theory. We will provide a geometrical description of the $\mathbb Z_2$ part in $\pi^n(M)$ analogous to Pontryagin's computation of the
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Quasi-derivation relations for multiple zeta values revisited Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-11-25 Masanobu Kaneko, Hideki Murahara, Takuya Murakami
We take another look at the so-called quasi-derivation relations in the theory of multiple zeta values, by giving a certain formula for the quasi-derivation operator. In doing so, we are not only able to prove the quasi-derivation relations in a simpler manner but also give an analog of the quasi-derivation relations for finite multiple zeta values.
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Modular forms and q-analogues of modified double zeta values Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-11-11 Henrik Bachmann
We present explicit formulas for Hecke eigenforms as linear combinations of q-analogues of modified double zeta values. As an application, we obtain period polynomial relations and sum formulas for these modified double zeta values. These relations have similar shapes as the period polynomial relations of Gangl, Kaneko and Zagier and the usual sum formulas for classical double zeta values.
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A note on the Sturm bound for Siegel modular forms of type (k, 2) Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-10-30 Hirotaka Kodama
We study analogues of Sturm’s bounds for vector valued Siegel modular forms of type (k, 2), which was already studied by Sturm in the case of an elliptic modular form and by Choi–Choie–Kikuta, Poor–Yuen and Raum–Richter in the case of scalar valued Siegel modular forms.
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Twisted adjoint L-values, dihedral congruence primes and the Bloch–Kato conjecture Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-10-29 Neil Dummigan
We show that a dihedral congruence prime for a normalised Hecke eigenform f in $$S_k(\Gamma _0(D),\chi _D)$$ , where $$\chi _D$$ is a real quadratic character, appears in the denominator of the Bloch–Kato conjectural formula for the value at 1 of the twisted adjoint L-function of f. We then use a formula of Zagier to prove that it appears in the denominator of a suitably normalised $$L(1,{\mathrm {ad}}^0(g)\otimes
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The contact geometry of the spatial circular restricted 3-body problem Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-09-10 WanKi Cho, Hyojin Jung, GeonWoo Kim
We show that a hypersurface of the regularized, spatial circular restricted three-body problem is of contact type whenever the energy level is below the first critical value (the energy level of the first Lagrange point) or if the energy level is slightly above it. A dynamical consequence is that there is no blue sky catastrophe in this energy range.
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On some classes of $${\mathbb {Z}}$$-graded Lie algebras Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Stefano Marini, Costantino Medori, Mauro Nacinovich
We study finite dimensional almost- and quasi-effective prolongations of nilpotent $${\mathbb {Z}}$$ -graded Lie algebras, especially focusing on those having a decomposable reductive structural subalgebra. Our assumptions generalize effectiveness and algebraicity and are appropriate to obtain Levi–Malcev and Levi–Chevalley decompositions and precisions on the heigth and other properties of the prolongations
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A construction of p-adic Hurwitz–Lerch L-function Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Selin Selen Özbek, Mehmet Cenkci
We derive the existence of p-adic Hurwitz–Lerch L-function by means of a method provided by Washington. This function is a generalization of the one-variable p-adic L-function of Kubota and Leopoldt, and two-variable p-adic L-function of Fox. We also deduce divisibility properties of generalized Apostol–Bernoulli polynomials, in particular establish Kummer-type congruences for them.
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A characterization of complex space forms via Laplace operators Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Andrea Loi, Filippo Salis, Fabio Zuddas
Inspired by the work of Lu and Tian (Duke Math J 125(2):351–387, 2004), in this paper we address the problem of studying those Kähler manifolds satisfying the $$\Delta$$ Δ -property, i.e. such that on a neighborhood of each of its points the k th power of the Kähler Laplacian is a polynomial function of the complex Euclidean Laplacian, for all positive integer k (see below for its definition). We prove
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Differential geometry of immersed surfaces in three-dimensional normed spaces Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Vitor Balestro, Horst Martini, Ralph Teixeira
In this paper we study curvature types of immersed surfaces in three-dimensional (normed or) Minkowski spaces. By endowing the surface with a normal vector field, which is a transversal vector field given by the ambient Birkhoff orthogonality, we get an analogue of the Gauss map. Then we can define concepts of principal, Gaussian, and mean curvatures in terms of the eigenvalues of the differential
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On the Chow ring of Fano varieties of type S2 Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Robert Laterveer
Fatighenti and Mongardi have defined Fano varieties of type S6 as zero loci of a certain vector bundle on the Grassmannian $\hbox{Gr}(2,10)$. These varieties have 3 Hodge structures of K3 type in their cohomology. We show that the Chow ring of these varieties also displays "K3 type" behaviour.
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Linking complex analytic to nonstandard algebraic geometry Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Adel Khalfallah, Siegmund Kosarew
In this paper, we sketch some constructions providing a link between complex-analytic geometry and nonstandard algebraic geometry via a categorical point of view. The analytic category is seen as a completed fiber of a family of nonstandard algebraic geometries by applying a standard part functor. We indicate how various notions of analytic objects fit into this context (as for example banachanalytic
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Explicit uniformizers for certain totally ramified extensions of the field of p-adic numbers Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-04-01 Hugues Bellemare, Antonio Lei
Let $p$ be an odd prime number. We construct explicit uniformizers for the totally ramified extension $\mathbb{Q}_p(\zeta_{p^2},\sqrt[p]{p})$ of the field of $p$-adic numbers $\mathbb{Q}_p$, where $\zeta_{p^2}$ is a primitive $p^2$-th root of unity.
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On a type of maximal abelian torsion free subgroups of connected Lie groups Abh. Math. Semin. Univ. Hambg. (IF 0.4) Pub Date : 2020-02-12 Abdelhak Abouqateb, Mehdi Nabil
For an arbitrary real connected Lie group G we define $$\mathrm {p}(G)$$ p ( G ) as the maximal integer p such that $$\mathbb {Z}^p$$ Z p is isomorphic to a discrete subgroup of G and $$\mathrm {q}(G)$$ q ( G ) is the maximal integer q such that $$\mathbb {R}^q$$ R q is isomorphic to a closed subgroup of G . The aim of this paper is to investigate properties of these two invariants. We will show that