Let X be a proper smooth variety having an affine open subset defined by the normic equation $N_{k(\surd a,\surd b)/k}\left(x\right)=Q(t₁,...,tₘ)²$ over a number field k. We prove that: (1) the failure of the local-global principle for zero-cycles is controlled by the Brauer group of X; (2) the analogue for rational points is also valid assuming Schinzel’s hypothesis.

Let $R$ be a 2-dimensional normal excellent henselian local domain in which $2$ is invertible and let $L$ and $k$ be its fraction field and residue field respectively. Let ${\Omega }_R$ be the set of rank 1 discrete valuations of $L$ corresponding to codimension 1 points of regular proper models of $SpecR$. We prove that a quadratic form $q$ over $L$ satisfies the local-global principle with respect to ${\Omega }_R$ in the following two cases: (1) $q$ has rank 3 or 4; (2) $q$ has rank $\ge 5$ and $R=A\left[\right[y\left]\right]$, where $A$ is a complete discrete valuation ring with...

Soient $X$ un espace analytique affinoïde réduit sur un corps $K$ complet pour une valeur absolue non archimédienne, $r:X\to \widehat{X}$ sa réduction canonique et $p\in \widehat{X}$ un point de la variété algébrique affine $\widehat{X}$. Ce travail décrit la singularité du point $p$ à l’aide d’objets associés à l’espace $X$: la localisation formelle ${𝒪}_{X,\left(p\right)}$ qui est une $K$-algèbre noethérienne de spectre maximal $r^{-1}\left(p\right)$ et dont la réduction est ${𝒪}_{\widehat{X},\left(p\right)}$ ; un complété formel ${𝒪}_{X,\left(p\right)}$ qui est une $K$-algèbre noethérienne dont la réduction est ${𝒪}_{\widehat{X},\left(p\right)}$. Les résultats essentiels sont obtenus...

Let $K$ be a field of characteristic $p\>0$, $C$ a proper, smooth, geometrically connected curve over $K$, and 0 and $\infty$ two $K$-rational points on $C$. We show that any representation of the local Galois group at $\infty$ extends to a representation of the fundamental group of $C-\{0,\infty \}$ which is tamely ramified at 0, provided either that $K$ is separately closed or that $C$ is ${\mathbf{P}}^1$. In the latter case, we show there exists a unique such extension, called “canonical”, with the property that the image of the geometric fundamental group...

Let $X$ be the wonderful compactification of a connected adjoint semisimple group $G$ defined over a number field $K$. We prove Manin’s conjecture on the asymptotic (as $T\to \infty$) of the number of $K$-rational points of $X$ of height less than $T$, and give an explicit construction of a measure on $X\left(𝔸\right)$, generalizing Peyre’s measure, which describes the asymptotic distribution of the rational points $𝐆\left(K\right)$ on $X\left(𝔸\right)$. Our approach is based on the mixing property of $L^2(𝐆\left(K\right)\setminus 𝐆\left(𝔸\right))$ which we obtain with a rate of convergence.

The Manin conjecture is established for a split singular del Pezzo surface of degree four, with singularity type ${\mathbf{A}}_4$.

We prove Manin’s conjecture for a del Pezzo surface of degree six which has one singularity of type ${\mathbf{A}}_2$. Moreover, we achieve a meromorphic continuation and explicit expression of the associated height zeta function.

The first and second moments are established for the family of quadratic Dirichlet L-functions over the rational function field at the central point s=1/2, where the character χ is defined by the Legendre symbol for polynomials over finite fields and runs over all monic irreducible polynomials P of a given odd degree. Asymptotic formulae are derived for fixed finite fields when the degree of P is large. The first moment obtained here is the function field analogue of a result due to Jutila in the...

This paper establishes new bridges between zeta functions in number theory and modern harmonic analysis, namely between the class of complex functions, which contains the zeta functions of arithmetic schemes and closed with respect to product and quotient, and the class of mean-periodic functions in several spaces of functions on the real line. In particular, the meromorphic continuation and functional equation of the zeta function of an arithmetic scheme with its expected analytic shape is shown...

Soit $X$ un schéma projectif intègre défini sur un corps de nombres $F$ ; soit $L$ un fibré en droites ample sur $X$ muni d’une métrique adélique semi-positive au sens de Zhang. Les résultats principaux de cet article sont :(1)Une formule qui calcule les hauteurs locales (relativement à $L$) d’un diviseur de Cartier sur $X$ comme des « mesures de Mahler » généralisées, c’est-à-dire les intégrales de fonctions de Green pour $D$ contre des mesures associées à $L$ ;(2)Un théorème d’équidistribution des points de « petite »...

Let $N\ge 1$ be an integer. Let $X_0\left(N\right)$ be the modular curve over $\mathbf{Z}$, as constructed by Katz and Mazur. The minimal resolution of $X_0\left(N\right)$ over $\mathbf{Z}[1/6]$ is computed. Let $p\ge 5$ be a prime, such that $N=p^{2}M$, with $M$ prime to $p$. Let $n=(p^2-1)/2$. It is shown that $X_0\left(N\right)$ has stable reduction at $p$ over $\mathbf{Q}\left[\sqrt[n]{p}\right]$, and the fibre at $p$ of the stable model is computed.