Let $F$ be a $p$-adic field of characteristic 0, and let $M$ be an $F$-Levi subgroup of a connected reductive $F$-split group such that $\Pi _{i=1}^{r}\,\text{S}{{\text{L}}_{ni}}\,\subseteq \,M\,\subseteq \,\Pi _{i=1}^{r}\,\text{G}{{\text{L}}_{ni}}$ for positive integers $r$ and ${{n}_{i}}$. We prove that the Plancherel measure for any unitary supercuspidal representation of $M\left( F \right)$ is identically transferred under the local Jacquet–Langlands type correspondence between $M$ and its $F$-inner forms, assuming a working hypothesis that Plancherel measures are invariant on a certain set. This work extends the result of Muić and Savin (2000) for Siegel Levi subgroups of the groups $\text{S}{{\text{O}}_{4n}}$ and $\text{S}{{\text{p}}_{4n}}$ under the local Jacquet–Langlands correspondence. It can be applied to a simply connected simple $F$-group of type ${{E}_{6}}$ or ${{E}_{7}}$, and a connected reductive $F$-group of type ${{A}_{n}},\,{{B}_{n}},\,{{C}_{n}}$ or ${{D}_{n}}$.

Soit $\text{G}$ un groupe réductif $p$-adique, et soit $\text{R}$ un corps algébriquement clos. Soit $\text{ }\!\!\pi\!\!\text{ }$ une représentation lisse de $\text{G}$ dans un espace vectoriel $\text{V}$ sur $\text{R}$. Fixons un sous-groupe ouvert et compact $\text{K}$ de $\text{G}$ et une représentation lisse irréductible $\varrho$ de $\text{K}$ dans un espace vectoriel $\text{W}$ de dimension finie sur $\text{R}$. Sur l'espace $\text{Ho}{{\text{m}}_{\text{K}}}(\text{W,}\,\text{V)}$ agit l'algèbre d'entrelacement $\mathcal{H}(\text{G,}\,\text{K,}\,\text{W)}$. Nous examinons la compatibilité de ces constructions avec le passage aux représentations contragrédientes ${{\text{V}}^{\vee }}$ et ${{\text{W}}^{\vee }}$, et donnons en particulier des conditions sur $\text{W}$ ou sur la caractéristique de $\text{R}$ pour que le comportement soit semblable au cas des représentations complexes. Nous prenons un point de vue abstrait, n'utilisant que des propriétés générales de $\text{G}$. Nous terminons par une application á la théorie des types pour le groupe $\text{G}{{\text{L}}_{n}}$ et ses formes intérieures sur un corps local non archimédien.

In this paper we regularize the Kepler problem on ${{S}^{3}}$ in several different ways. First, we perform a Moser-type regularization. Then, we adapt the Ligon–Schaaf regularization to our problem. Finally, we show that the Moser regularization and the Ligon–Schaaf map we obtained can be understood as the composition of the corresponding maps for the Kepler problem in Euclidean space and the gnomonic transformation.

For a Lie group $G$, we show that the map $C_{c}^{\infty }\,\left( G \right)\,\times \,C_{c}^{\infty }\,\left( G \right)\,\to \,C_{c}^{\infty }\,\left( G \right),\,\left( \gamma ,\,\eta \right)\mapsto \,\gamma \,*\,\eta $ taking a pair of test functions to their convolution, is continuous if and only if $G$ is $\sigma -$compact. More generally, consider $r,\,s,\,t\,\in {{\mathbb{N}}_{0}}\,\cup \,\left\{ \infty \right\}$ with $t\,\le \,r\,+\,s$, locally convex spaces ${{E}_{1}}\,,\,{{E}_{2}}$ and a continuous bilinear map $b:\,{{E}_{1}}\,\times \,{{E}_{2}}\,\to \,F$ to a complete locally convex space $F$. Let $\beta :\,C_{c}^{r}\,\left( G,\,{{E}_{1}} \right)\,\times \,C_{c}^{S}\,\left( G,\,{{E}_{2}} \right)\,\to$$C_{c}^{t}\,\left( G,\,F \right),\,\left( \gamma ,\,\eta \right)\,\mapsto \,\gamma \,*\,b\,\eta$ be the associated convolution map. The main result is a characterization of those $\left( G,\,r,s,t,b \right)$ for which $\beta$ is continuous. Convolution of compactly supported continuous functions on a locally compact group is also discussed as well as convolution of compactly supported ${{L}^{1}}$-functions and convolution of compactly supported Radon measures.

We consider the obstacle problem for the Schrödinger evolution in the exterior of the unit ball with Dirichlet boundary condition. Under radial symmetry we compute explicitly the fundamental solution for the linear Dirichlet Schrödinger propagator ${{e}^{it{{\Delta }_{D}}}}$ and give a robust algorithm to prove sharp ${{L}^{1}}\,\to \,{{L}^{\infty }}$ dispersive estimates. We showcase the analysis in dimensions $n\,=\,5,\,7$. As an application, we obtain global well-posedness and scattering for defocusing energy-critical $\text{NLS}$ on $\Omega \,=\,{{\mathbb{R}}^{n}}\backslash \overline{B\left( 0,\,1 \right)}$ with Dirichlet boundary condition and radial data in these dimensions.

Let $\mathfrak{A}$ be a ${{C}^{*}}$-algebra with real rank zero that has the stable weak cancellation property. Let $\Im $ be an ideal of $\mathfrak{A}$ such that $\Im $ is stable and satisfies the corona factorization property. We prove that

$$0\,\to \,\Im \,\to \mathfrak{A}\,\to \,\mathfrak{A}/\Im \,\to \,0$$

is a full extension if and only if the extension is stenotic and $K$-lexicographic. As an immediate application, we extend the classification result for graph ${{C}^{*}}$-algebras obtained by Tomforde and the first named author to the general non-unital case. In combination with recent results by Katsura, Tomforde, West, and the first named author, our result may also be used to give a purely $K$-theoretical description of when an essential extension of two simple and stable graph ${{C}^{*}}$-algebras is again a graph ${{C}^{*}}$- algebra.

This paper concerns the problem of existence of taut foliations among 3-manifolds. From the work of David Gabai we know that a closed 3-manifold with non-trivial second homology group admits a taut foliation. The essential part of this paper focuses on Seifert fibered homology 3-spheres. The result is quite different if they are integral or rational but non-integral homology 3-spheres. Concerning integral homology 3-spheres, we can see that all but the 3-sphere and the Poincaré 3-sphere admit a taut foliation. Concerning non-integral homology 3-spheres, we prove there are infinitely many that admit a taut foliation, and infinitely many without a taut foliation. Moreover, we show that the geometries do not determine the existence of taut foliations on non-integral Seifert fibered homology 3-spheres.

The paper presents a new proof of the infinitesimal rigidity of convex polyhedra. The proof is based on studying derivatives of the discrete Hilbert–Einstein functional on the space of “warped polyhedra” with a fixed metric on the boundary.

The situation is in a sense dual to using derivatives of the volume in order to prove the Gauss infinitesimal rigidity of convex polyhedra. This latter kind of rigidity is related to the Minkowski theorem on the existence and uniqueness of a polyhedron with prescribed face normals and face areas.

In the spherical space and in the hyperbolic-de Sitter space, there is a perfect duality between the Hilbert–Einstein functional and the volume, as well as between both kinds of rigidity.

We review some of the related work and discuss directions for future research.

Due to work of $\text{W}$. Parry it is known that the growth rate of a hyperbolic Coxeter group acting cocompactly on ${{\mathbb{H}}^{3}}$ is a Salem number. This being the arithmetic situation, we prove that the simplex group (3,5,3) has the smallest growth rate among all cocompact hyperbolic Coxeter groups, and that it is, as such, unique. Our approach provides a different proof for the analog situation in ${{\text{H}}^{2}}$ where $\text{E}$. Hironaka identified Lehmer's number as the minimal growth rate among all cocompact planar hyperbolic Coxeter groups and showed that it is (uniquely) achieved by the Coxeter triangle group (3,7).

We prove the congruence relation for the $\bmod -p$ reduction of Shimura varieties associated with a unitary similitude group $GU(n\,-\,1,\,1)$ over $\mathbb{Q}$ when $p$ is inert and $n$ odd. The case when $n$ is even was obtained by T. Wedhorn and O. Bültel, as a special case of a result of B. Moonen, when the $\mu$–ordinary locus of the $p$–isogeny space is dense. This condition fails in our case. We show that every supersingular irreducible component of the special fiber of $p-I\text{sog}$ is annihilated by a degree one polynomial in the Frobenius element $F$, which implies the congruence relation.

A new characterization of the uniform convexity of Banach space is obtained in the sense of the Bishop–Phelps–Bollobás theorem. It is also proved that the couple of Banach spaces $\left( X,Y \right)$ has the Bishop–Phelps–Bollobás property for every Banach space $Y$ when $X$ is uniformly convex. As a corollary, we show that the Bishop–Phelps–Bollobás theorem holds for bilinear forms on ${{\ell }_{p}}\,\times \,{{\ell }_{q}}$$\left( 1\,<p,q\,<\,\infty \right)$.

Let $\mathcal{V}$ be a variety of associative algebras generated by an algebra with 1 over a field of characteristic zero. This paper is devoted to the classification of the varieties $\mathcal{V}$ that are minimal of polynomial growth (i.e., their sequence of codimensions grows like ${{n}^{k}}$, but any proper subvariety grows like ${{n}^{t}}$ with $t\,<\,k$). These varieties are the building blocks of general varieties of polynomial growth.

It turns out that for $k\,\le \,4$ there are only a finite number of varieties of polynomial growth ${{n}^{k}}$, but for each $k\,>\,4$, the number of minimal varieties is at least $\left| F \right|$, the cardinality of the base field, and we give a recipe for their construction.

Let $\mathcal{H}$ and $\mathcal{K}$ be infinite-dimensional separable Hilbert spaces and $\text{Lat}\,\mathcal{H}$ the lattice of all closed subspaces oh $\mathcal{H}$. We describe the general form of pairs of bijective maps $\phi ,\,\psi :\,\text{Lat}\,\mathcal{H}\,\to \,\text{Lat}\,\mathcal{K}$ having the property that for every pair $U,\,V\,\in \,\text{Lat}\,\mathcal{H}$ we have $\mathcal{H}\,=\,U\,\oplus \,V\,\Leftrightarrow \,\mathcal{K}\,=\,\phi \left( U \right)\,\oplus \,\psi \,\left( V \right)$. Then we reformulate this theorem as a description of bijective image equality and kernel equality preserving maps acting on bounded linear idempotent operators. Several known structural results for maps on idempotents are easy consequences.

Let $E$ be an elliptic curve over $\mathbb{Q}$ that has good supersingular reduction at $p\,>\,3$. We construct what we call the $\pm /\pm $-Selmer groups of $E$ over the $\mathbb{Z}_{p}^{2}$-extension of an imaginary quadratic field $K$ when the prime $p$ splits completely over $K/\mathbb{Q}$, and prove that they enjoy a property analogous to Mazur's control theorem.

Furthermore, we propose a conjectural connection between the $\pm /\pm $-Selmer groups and Loeffler's two-variable $\pm /\pm $-$p$-adic $L$-functions of elliptic curves.

The main result of this paper is a characterization of the abelian varieties $B/K$ defined over Galois number fields with the property that the $L$-function $L\left( B/K;\,s \right)$ is a product of $L$-functions of non-$\text{CM}$ newforms over $Q$ for congruence subgroups of the form ${{\Gamma }_{1}}\,\left( N \right)$. The characterization involves the structure of End$\left( B \right)$, isogenies between the Galois conjugates of $B$, and a Galois cohomology class attached to $B/K$.

We call the varieties having this property strongly modular. The last section is devoted to the study of a family of abelian surfaces with quaternionic multiplication. As an illustration of the ways in which the general results of the paper can be applied, we prove the strong modularity of some particular abelian surfaces belonging to that family, and we show how to find nontrivial examples of strongly modular varieties by twisting.

The complete set of minimal obstructions for embedding graphs into the torus is still not determined. In this paper, we present all obstructions for the torus of connectivity 2. Furthermore, we describe the building blocks of obstructions of connectivity 2 for any orientable surface.

This article establishes a sufficient condition for Kobayashi hyperbolicity of unbounded domains in terms of curvature. Specifically, when $\Omega \,\subset \,{{\mathbb{C}}^{n}}$ corresponds to a sub-level set of a smooth, real-valued function Ψ such that the form $\omega \,=\,\mathbf{i}\partial \bar{\partial }\Psi $ is Kähler and has bounded curvature outside a bounded subset, then this domain admits a hermitian metric of strictly negative holomorphic sectional curvature.

We prove that, in a setting of local Dirichlet forms on metric measure spaces, a two-sided sub-Gaussian estimate of the heat kernel is equivalent to the conjunction of the volume doubling property, the elliptic Harnack inequality, and a certain estimate of the capacity between concentric balls. The main technical tool is the equivalence between the capacity estimate and the estimate of a mean exit time in a ball that uses two-sided estimates of a Green function in a ball.

Let ${{\mathbb{F}}_{q}}\left[ t \right]$ denote the polynomial ring over the finite field ${{\mathbb{F}}_{q}}$. We employ Wooley's new efficient congruencing method to prove certain multidimensional Vinogradov-type estimates in ${{\mathbb{F}}_{q}}\left[ t \right]$. These results allow us to apply a variant of the circle method to obtain asymptotic formulas for a system connected to the problem about linear spaces lying on hypersurfaces defined over ${{\mathbb{F}}_{q}}\left[ t \right]$.

The purpose of this note is to introduce a method for proving the non-existence of rational points on a coarse moduli space $X$ of abelian varieties over a given number field $K$ in cases where the moduli problem is not fine and points in $X\left( K \right)$ may not be represented by an abelian variety (with additional structure) admitting a model over the field $K$. This is typically the case when the abelian varieties that are being classified have even dimension. The main idea, inspired by the work of Ellenberg and Skinner on the modularity of $\mathbb{Q}$-curves, is that one may still attach a Galois representation of $\text{Gal}\left( \bar{K},\,K \right)$ with values in the quotient group $\text{GL}\left( {{T}_{\ell }}\left( A \right) \right)/\,\text{Aut}\left( A \right)$ to a point $P\,=\,\left[ A \right]\,\in \,X\left( K \right)$ represented by an abelian variety $A/\bar{K}$, provided $\text{Aut}\left( A \right)$ lies in the centre of $\text{GL}\left( {{T}_{\ell }}\left( A \right) \right)$. We exemplify our method in the cases where $X$ is a Shimura curve over an imaginary quadratic field or an Atkin–Lehner quotient over $\mathbb{Q}$.