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Mathematics

Mathematics

Recent Submissions

  • Bountis, Tassos; Vanhaecke, Pol (Physics Letters A, 2016-12-09)
    Abstract We use a strong version of the Painlevé property to discover and characterize a new class of n-dimensional Hamiltonian Lotka–Volterra systems, which turn out to be Liouville integrable as well as superintegrable. ...
  • Antonopoulos, Chris G.; Skokos, Charalampos; Bountis, Tassos; Flach, Sergej (Chaos, Solitons & Fractals, 2017-11-01)
    Abstract In the study of subdiffusive wave-packet spreading in disordered Klein–Gordon (KG) nonlinear lattices, a central open question is whether the motion continues to be chaotic despite decreasing densities, or tends ...
  • La Torre, Davide; Marsiglio, Simone; Mendivil, Franklin; Privileggi, Fabio (Communications in Nonlinear Science and Numerical Simulation, 2018-05-01)
    Abstract We analyze a multi-sector growth model subject to random shocks affecting the two sector-specific production functions twofold: the evolution of both productivity and factor shares is the result of such exogenous ...
  • Betancor, Jorge J.; Castro, Alejandro J.; Fariña, Juan C.; Rodríguez-Mesa, L. (Journal of Mathematical Analysis and Applications, 2017-03-01)
    Abstract In this paper we consider conical square functions in the Bessel, Laguerre and Schrödinger settings where the functions take values in UMD Banach spaces. Following a recent paper of Hytönen, van Neerven and Portal ...
  • Otero, Daniel; La Torre, Davide; Michailovich, Oleg; Vrscay, Edward R. (Signal Processing, 2017-05-01)
    Abstract The concept of a mapping, which takes its values in an infinite-dimensional functional space, has been studied by the mathematical community since the third decade of the last century. This effort has produced a ...
  • Nordström, Kenneth (Linear Algebra and its Applications, 2018-02-01)
    Abstract This note is a sequel to an earlier study (Nordström [7]) on convexity properties of the inverse and Moore–Penrose inverse, in which the following question was raised. Given nonnegative definite matrices A and B ...
  • Wegner, Sven-Ake (Journal of Pure and Applied Algebra, 2017-11-01)
    Abstract Consider an exact category in the sense of Quillen. Assume that in this category every morphism has a kernel and that every kernel is an inflation. In their seminal 1982 paper, Beĭlinson, Bernstein and Deligne ...
  • Melnykov, Igor; Melnykov, Volodymyr (Statistics & Probability Letters, 2014-01-01)
    Abstract The K-means algorithm is commonly used with the Euclidean metric. While the use of Mahalanobis distances seems to be a straightforward extension of the algorithm, the initial estimation of covariance matrices can ...
  • Kominis, Yannis; Kovanis, Vassilios; Bountis, Tassos (Physical Review, 2017-10-16)
    Coupled semiconductor lasers are systems possessing complex dynamics that are interesting for numerous applications in photonics. In this work, we investigate the existence and the stability of asymmetric phase-locked ...
  • Kominis, Yannis; Bountis, Tassos; Flach, Sergej (ArXiv, 2017-06-23)
    We analyze the stability of a non-Hermitian coupler with respect to modulational inhomogeneous perturbations in the presence of unbalanced gain and loss. At the parity-time (PT) symmetry point the coupler is unstable. ...
  • Kominis, Yannis; Kovanis, Vassilios; Bountis, Tassos (ArXiv, 2017-10-04)
    The fundamental active photonic dimer consisting of two coupled quantum well lasers is inves-tigated in the context of the rate equation model. Spectral transition properties and exceptional points are shown to occur under ...
  • Wei, Dongming; Skrzypacz, Piotr; Yu, Xijun (Journal of Applied Mathematics, 2017-07-13)
    Some novel traveling waves and special solutions to the 1D nonlinear dynamic equations of rod and beam of power-law materials are found in closed forms. The traveling solutions represent waves of high elevation that ...
  • Wei, D.; Kadyrov, S.; Kazbek, Z. (Applied and Computational Mechanics, 2017)
    Phase plane analysis of the nonlinear spring-mass equation arising in modeling vibrations of a lumped mass attached to a graphene sheet with a fixed end is presented. The nonlinear lumped-mass model takes into account the ...
  • Kominis, Yannis; Bountis, Tassos; Flach, Sergej (Scientific Reports, 2016-09-19)
    We consider the asymmetric active coupler (AAC) consisting of two coupled dissimilar waveguides with gain and loss. We show that under generic conditions, not restricted by parity-time symmetry, there exist finite-power, ...
  • Benner, Peter; Mach, Thomas (Computing (Vienna/New York), 2010-06-09)
    The hierarchical ( backslashfancyscriptH -) matrix format allows storing a variety of dense matrices from certain applications in a special data-sparse way with linear-polylogarithmic complexity. Many operations from linear ...
  • Bonet, José; Wegner, Sven Ake (Functiones et Approximatio, Commentarii Mathematici, 2011)
    We establish a criterion to decide when a countable projective limit of countable inductive limits of normed spaces is bornological. We compare the conditions occurring within our criterion with well-known abstract conditions ...
  • Mach, Thomas; Vandebril, Raf (SIAM Journal on Matrix Analysis and Applications, 2014)
    In this paper we discuss the deflation criterion used in the extended QR algorithm based on the chasing of rotations. We provide absolute and relative perturbation bounds for this deflation criterion. Further, we present ...
  • Mach, Thomas; Van Barel, Marc; Vandebril, Raf (Journal of Computational and Applied Mathematics, 2014-12-15)
    In inverse eigenvalue problems one tries to reconstruct a matrix, satisfying some constraints, given some spectral information. Here, two inverse eigenvalue problems are solved. First, given the eigenvalues and the first ...
  • Mach, Thomas; Pranić, Miroslav S.; Vandebril, Raf (Electronic Transactions on Numerical Analysis, 2014)
    It has been shown that approximate extended Krylov subspaces can be computed, under certain assumptions, without any explicit inversion or system solves. Instead, the vectors spanning the extended Krylov space are retrieved ...
  • Aurentz, Jared L.; Mach, Thomas; Vandebril, Raf; Watkins, David S. (Electronic Transactions on Numerical Analysis, 2015)
    A fast Fortran implementation of a variant of Gragg's unitary Hessenberg QR algorithm is presented. It is proved, moreover, that all QR- And QZ-like algorithms for the unitary eigenvalue problems are equivalent. The algorithm ...

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