Static and dynamic Melvin universes
We briefly review the known properties of Melvin's magnetic universe and study the propagation of test charged matter waves in this static spacetime. Moreover, the possible correspondence between the wave perturbations on the background Melvin universe and the motion of charged test particles is discussed. Next, we explore a simple scenario for turning Melvin's static universe into one that undergoes gravitational collapse. In the resulting dynamic gravitational field, the formation of cosmic double-jet configurations is emphasized.
Flexoelectric switching in cholesteric blue phases
We present computer simulations of the response of a flexoelectric blue phase network, either in bulk or under confinement, to an applied field. We find a transition in the bulk between the blue phase I disclination network and a parallel array of disclinations along the direction of the applied field. Upon switching off the field, the system is unable to reconstruct the original blue phase but gets stuck in a metastable phase. Blue phase II is comparatively much less affected by the field.
De la Vallée Poussin interpolation method for image resizing
The aim of this talk is to show how de la Vallee Poussin type interpolation based on Chebyshev zeros of rst kind, can be applied to resize an arbitrary color digital image. In fact, using such kind of approximation, we get an image scaling method running for any desired scaling factor or size, in both downscaling and upscaling. The peculiarities and the performance of such method will be discussed.
Altered Brain Criticality in Schizophrenia: New Insights From Magnetoencephalography
Schizophrenia has a complex etiology and symptomatology that is difficult to untangle. After decades of research, important advancements toward a central biomarker are still lacking. One of the missing pieces is a better understanding of how non-linear neural dynamics are altered in this patient population. In this study, the resting-state neuromagnetic signals of schizophrenia patients and healthy controls were analyzed in the framework of criticality.
Momentum recoil in the relativistic two-body problem: Higher-order tails
In the description of the relativistic two-body interaction, together with the effects of energy and
angular momentum losses due to the emission of gravitational radiation, one has to take into account also
the loss of linear momentum, which is responsible for the recoil of the center-of-mass of the system. We
compute higher-order tail (i.e., tail-of-tail and tail-squared) contributions to the linear momentum flux
for a nonspinning binary system either along hyperboliclike or ellipticlike orbits.
Convergence in probability of the Mallows and GCV wavelet and Fourier regularization methods
Wavelet and Fourier regularization methods are effective for the nonparametric regression problem. We prove that the loss function evaluated for the regularization parameter chosen through GCV or Mallows criteria is asymptotically equivalent in probability to its minimum over the regularization parameter. © 2001 Elsevier Science B.V.
The Knapsack Problem with forfeit sets
This work introduces a novel extension of the 0/1 Knapsack Problem in which we consider the existence of so-called forfeit sets. A forfeit set is a subset of items of arbitrary cardinality, such that including a number of its elements that exceeds a predefined allowance threshold implies some penalty costs to be paid in the objective function value. A global upper bound on these allowance violations is also considered.