Geodesic excursions into cusps in finite-volume hyperbolic manifolds

18 pages, no figures.-- MSC1991 codes: Primary: 53C22; Secondary: 30F40, 58F17.MR#: MR1214056 (94d:53067)Zbl#: Zbl 0793.53052The main goal of the paper is to prove that, for a given non-compact hyperbolic $n$-manifold $M$ of finite volume, $p\in M$, and a number $\alpha$, $0\leq\alpha \leq 1$, the Hausdorff dimension of the set \{v\in T\sb p\sp 1(M): \lim\sb{t\to\infty} \sup (\text{dist} (\gamma\sb v(t),p)/t)\geq \alpha\} is equal to $n(1-\alpha)$, where \gamma\sb v(t) is the geodesic in $M$ emanating from $p$ in the direction of $v$. This generalize a result of [Acta Math. 149, 215-237 (1982)] that, for almost every direction $v$, such a limit is $1/n$, and it is one for just a countable set of directions $v$.\par However we remark that one has to restrict this claim to the class of hyperbolic manifolds with only Abelian parabolic cusps because the authors assume in fact such property for all considered manifolds $M$ [source: Zentralblatt MATH].Research supported by a grant from CICYT, Ministerio de Educación y Ciencia, Spain.Publicad

Uniform asymptotic estimates of hypergeometric functions appearing in Potential Theory

19 pages, no figures.-- MSC1991 codes: 33C05, 33C55, 31B15.MR#: MR1393128 (98b:33007)Zbl#: Zbl 0864.33001The solution of a Dirichlet problem for the Laplace-Beltrami operator with Bergman metric in the unit ball in the complex $n$-dimensional space can be expressed in terms of integrals of which the kernel can be expanded in spherical harmonics. The coefficients in this expansion contain ratios of Gauss hypergeometric functions of the form $F(p,q;p+q+n;r^2)/ F(p,q;p+q+n;1)$. The paper studies the uniform asymptotic behaviour of $F(q,mq;q+mq+n;t)$ for large values of $q$. Several results are formulated as inequalities for certain integrals containing ratios of hypergeometric functions [Zentralblatt MATH].Research of the second author was supported by a grant of the CICYT, Ministerio de Educación y Ciencia, Spain.Publicad

Isoperimetric inequalities in Riemann surfaces of infinite type

75 pages, 1 figure.-- MSC2000 code: 30F45.MR#: MR1715412 (2000j:30075)Zbl#: Zbl 0935.30028Research partially supported by a grant from Dirección General de Enseñanza Superior (Ministerio de Educación y Ciencia), Spain.Publicad

Quantitative mixing results and inner functions

19 pages, no figures.-- MSC2000 codes: 30D05, 30D50, 37A05, 37A25, 37F10, 28D05, 11K55.MR#: MR2262783 (2007j:37003)Zbl#: Zbl 1125.30019We study in this paper estimates on the size of the sets of points which are well approximated by orbits of other points under certain dynamical systems. We apply the results obtained to the particular case of the dynamical system generated by inner functions in the unit disk of the complex plane.D. Pestana was supported by Grants BFM2003-04780 and BFM-2003-06335-C03-02, Ministerio de Ciencia y Tecnología, Spain. J. L. Fernández and M. V. Melián were supported by Grant BFM2003-04780 from Ministerio de Ciencia y Tecnología, Spain.Publicad

Distortion of boundary sets under inner functions. II

33 pages, no figures.-- MSC2000 codes: 32A30, 30C85, 30D50.MR#: MR1379286 (97b:30035)Zbl#: Zbl 0847.32005We present a study of the metric transformation properties of inner functions of several complex variables. Along the way we obtain fractional dimensional ergodic properties of classical inner functions.Publicad

Generalized weighted Sobolev spaces and applications to Sobolev orthogonal polynomials, I

36 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.-- Part II of this paper published in: Approx. Theory Appl. 18(2): 1-32 (2002), available at: http://e-archivo.uc3m.es/handle/10016/6483MR#: MR2047389 (2005k:42062)Zbl#: Zbl 1081.42024In this paper we present a definition of Sobolev spaces with respect to general measures, prove some useful technical results, some of them generalizations of classical results with Lebesgue measure and find general conditions under which these spaces are complete. These results have important consequences in approximation theory. We also find conditions under which the evaluation operator is bounded.Research by first (J.M.R.), third (E.R.) and fourth (D.P.) authors was partially supported by a grant from DGI (BFM 2000-0206-C04-01), Spain.Publicad

Approximation theory for weighted Sobolev spaces on curves

17 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.MR#: MR1882649 (2003c:42002)In this paper we present a definition of weighted Sobolev spaces on curves and find general conditions under which the spaces are complete. We also prove the density of the polynomials in these spaces for non-closed compact curves and, finally, we find conditions under which the multiplication operator is bounded on the completion of polynomials. These results have applications to the study of zeroes and asymptotics of Sobolev orthogonal polynomials.Research of V. Álvarez, D. Pestana and J.M. Rodríguez partially supported by a grant from DGI, BFM2000-0206-C04-01, Spain.Publicad