Garcia-Colin N.,Infotec Research Center novacion En Tecnologias Of La Informacion municacion |
Raggi M.,National Autonomous University of Mexico |
Roldan-Pensado E.,Institute Matematicas
Discrete and Computational Geometry | Year: 2017
The tolerant Tverberg theorem generalizes Tverberg’s theorem by introducing a new parameter t called tolerance. It states that there is a minimal number N so that any set of at least N points in (Formula presented.) can be partitioned into r disjoint sets such that they remain intersecting even after removing any t points from X. In this paper we give an asymptotically tight bound for the tolerant Tverberg Theorem when the dimension and the size of the partition are fixed. To achieve this, we study certain partitions of order-type homogeneous sets and use a generalization of the Erdős–Szekeres theorem. As far as we know, this is the first time that a Ramsey-type theorem has been used to prove a Tverberg-type result. © 2017 Springer Science+Business Media New York
Castillo Villalba C.M.P.,Institute Matematicas |
Colombo F.,Polytechnic of Milan |
Gantner J.,Vienna University of Technology |
Gonzalez-Cervantes J.O.,E.S.F.M. del I.P.N.
Complex Analysis and Operator Theory | Year: 2015
In this paper we begin the study of some important Banach spaces of slice hyperholomorphic functions, namely the Bloch, Besov and weighted Bergman spaces, and we also consider the Dirichlet space, which is a Hilbert space. The importance of these spaces is well known, and thus their study in the framework of slice hyperholomorphic functions is relevant, especially in view of the fact that this class of functions has recently found several applications in operator theory and in Schur analysis. We also discuss the property of invariance of these function spaces with respect to Möbius maps by using a suitable notion of composition. © 2014, Springer Basel.
Hubard I.,Institute Matematicas |
Mixer M.,Wentworth Institute of Technology |
Pellicer D.,National Autonomous University of Mexico |
Weiss A.I.,York University
Discrete and Computational Geometry | Year: 2015
Up to isomorphism, there are six fixed-point free crystallographic groups in Euclidean 3-space (Formula presented.) generated by twists (screw motions). In each case, an orientable 3-manifold is obtained as the quotient of (Formula presented.) by such a group. The cubic tessellation of (Formula presented.) induces tessellations on each such manifold. The corresponding classification for the 3-torus and the didicosm were classified as ‘equivelar toroids’ and ‘cubic tessellation of the didicosm’ in previous works. This paper concludes the classification of cubic tessellations on the remaining four orientable manifolds. © 2015, Springer Science+Business Media New York.
Kotani M.,Tohoku University |
Schulz-Baldes H.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Villegas-Blas C.,Institute Matematicas
Journal of Mathematical Physics | Year: 2014
At the interface of two two-dimensional quantum systems, there may exist interface currents similar to edge currents in quantum Hall systems. It is proved that these interface currents are macroscopically quantized by an integer that is given by the difference of the Chern numbers of the two systems. It is also argued that at the interface between two time-reversal invariant systems with half-integer spin, one of which is trivial and the other non-trivial, there are dissipationless spin-polarized interface currents. © 2014 AIP Publishing LLC.
Coronel A.D.C.,Institute Quimica Organica |
Gargiulo M.E.,Institute Matematicas |
Varetti E.L.,National University of La Plata |
Fernandez L.E.,National University of Tucuman
Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences | Year: 2011
The vibrational properties of the asymmetrical thionyl halides FS(O)Cl, CF3S(O)F and CF3S(O)Cl were studied by means of density functional theory (DFT) techniques. The available experimental data and assignments for these molecules were compared with the theoretical results and revised. These data were subsequently used in the definition of the corresponding scaled quantum mechanics (SQM) force fields. A set of internal force constants was also calculated from such force fields. © 2011 Verlag der Zeitschrift für Naturforschung.
Diaz A.,Institute Matematicas |
Jung C.,National Autonomous University of Mexico
Molecular Physics | Year: 2010
The assignment of molecular vibrations by diabatic correlation diagrams does not work in the form originally implemented by Rose and Kellman [J. Chem. Phys. 105, 7348 (1996)] for the class of states of CHBrClF where the two bend modes couple to rotating and counter-rotating motion. We show that an improved version of diabatic correlation, where we allow the variation of some additional parameters, works quite well. This improved diabatic correlation also provides a simplified Hamiltonian for the class of states under study. The results coming out of the improved correlation method are compared with the assignment coming out of a graphical method [C. Jung, E. Ziemniak, and H.S. Taylor, J. Chem. Phys. 115, 2499 (2001)]; they coincide perfectly.
Pellicer D.,Institute Matematicas |
Williams G.,University of Alaska Fairbanks
Electronic Journal of Combinatorics | Year: 2012
We discuss representations of non-finite polyhedra as quotients of regular polytopes. We provide some structural results about the minimal regular covers of non-finite polyhedra and about the stabilizer subgroups of their flags under the flag action of the automorphism group of the covering polytope. As motivating examples we discuss the minimal regular covers of the Archimedean tilings, and we construct explicit minimal regular covers for three of them.
O'Reilly-Regueiro E.,Institute Matematicas
Designs, Codes, and Cryptography | Year: 2010
It has been shown that if a (v, k, λ)-symmetric design with λ ≤ 3 admits a flag-transitive automorphism group G which acts primitively on points, then G must be of affine or almost simple type. Here we extend the result to λ = 4. © 2009 Springer Science+Business Media, LLC.