• SPATIAL CONTROL OF LOCALIZED OSCILLATIONS IN ARRAYS OF COUPLED LASER DIMERS 

  Shena, Joniald; Kominis, Yannis; Bountis, Anastasios; Kovanis, Vassilios (PHYSICAL REVIEW E, 2020)

  Arrays of coupled semiconductor lasers are systems possessing radically complex dynamics that makes them useful for numerous applications in beam forming and beam shaping. In this work, we investigate the spatial ...
• The Asymmetric Active Coupler: Stable Nonlinear Supermodes and Directed Transport 

  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, ...
• The effect of long–range interactions on the dynamics and statistics of 1D Hamiltonian lattices with on–site potential 

  Christodoulidi, H.; Bountis, Tassos; Drossos, L. (arXiv, 2018-04)

  We examine the role of long–range interactions on the dynamical and statistical properties of two 1D lattices with on–site potentials that are known to support discrete breathers: the Klein–Gordon (KG) lattice which ...
• Stability through asymmetry: Modulationally stable nonlinear supermodes of asymmetric non-Hermitian optical couplers 

  Kominis, Yannis; Bountis, Tassos; Flach, Sergej (Physical Review A, 2017-06-21)

  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. Suitable ...
• Spectral Signatures of Exceptional Points and Bifurcations in the Fundamental Active Photonic Dimer 

  Kominis, Yannis; Kovanis, Vassilios; Bountis, Tassos (arXiv, 2018-08)

  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 ...
• Lotka–Volterra systems satisfying a strong Painlevé property 

  Bountis, Tassos; Vanhaecke, Pol (Physics Letters A, 2016-09)

  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. These ...
• Homoclinic Points of 2-D and 4-D Maps via the Parametrization Method 

  Anastassiou, Stavros; Bountis, Tassos; B¨acker, Arnd (arXiv, 2017-09)

  An interesting problem in solid state physics is to compute discrete breather solutions in N coupled 1–dimensional Hamiltonian particle chains and investigate the richness of their interactions. One way to do this is to ...
• Exceptional Points in Two Dissimilar Coupled Diode Lasers 

  Kominis, Yannis; Choquette, Kent D.; Bountis, Anastassios; Kovanis, Vassilios (arXiv, 2018-06)

  We show the abundance of Exceptional Points in the generic asymmetric configuration of two coupled diode lasers, under nonzero optical detuning and differential pumping. We pinpoint the location of these points with ...
• Controllable Asymmetric Phase-Locked States of the Fundamental Active Photonic Dimer 

  Kominis, Yannis; Kovanis, Vassilios; Bountis, Tassos (arXiv, 2018-03-07)

  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 ...
• Analyzing Chaos in Higher Order Disordered Quartic-Sextic Klein-Gordon Lattices Using q-Statistics 

  Antonopoulos, Chris G.; Skokos, Charalampos; Bountis, Tassos; Flach, Sergej (arXiv, 2018-03-19)

  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 to become ...
• Lotka–Volterra systems satisfying a strong Painlevé property 

  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. ...
• Analyzing chaos in higher order disordered quartic-sextic Klein-Gordon lattices using q-statistics 

  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 ...
• Fractal attractors and singular invariant measures in two-sector growth models with random factor shares 

  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 ...
• Conical square functions associated with Bessel, Laguerre and Schrödinger operators in UMD Banach spaces 

  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 ...
• On the theory of function-valued mappings and its application to the processing of hyperspectral images 

  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 ...
• A note on the convexity of the Moore–Penrose inverse 

  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 ...
• The heart of the Banach spaces 

  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 ...
• On K-means algorithm with the use of Mahalanobis distances 

  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 ...
• Controllable asymmetric phase-locked states of the fundamental active photonic dimer 

  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 ...
• Stability Through Asymmetry: Modulationally Stable Nonlinear Supermodes of Asymmetric non-Hermitian Optical Couplers 

  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. ...

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