Search results for " oscillation"

Underlying A_4 Symmetry for the Neutrino Mass Matrix and the Quark Mixing Matrix

2002

The discrete non-Abelian symmetry $A_4$, valid at some high-energy scale, naturally leads to degenerate neutrino masses, without spoiling the hierarchy of charged-lepton masses. Realistic neutrino mass splittings and mixing angles (one of which is necessarily maximal and the other large) are then induced radiatively in the context of softly broken supersymmetry. The quark mixing matrix is also calculable in a similar way. The mixing parameter $U_{e3}$ is predicted to be imaginary, leading to maximal CP violation in neutrino oscillations. Neutrinoless double beta decay and $\tau \to \mu \gamma$ should be in the experimentally accessible range.

Shell-like structures in our cosmic neighbourhood

2016

Signatures of the processes in the early Universe are imprinted in the cosmic web. Some of them may define shell-like structures characterised by typical scales. We search for shell-like structures in the distribution of nearby rich clusters of galaxies drawn from the SDSS DR8. We calculate the distance distributions between rich clusters of galaxies, and groups and clusters of various richness, look for the maxima in the distance distributions, and select candidates of shell-like structures. We analyse the space distribution of groups and clusters forming shell walls. We find six possible candidates of shell-like structures, in which galaxy clusters have maxima in the distance distribution…

Mixed-mode oscillation-incrementing bifurcations and a devil’s staircase from a nonautonomous, constrained Bonhoeffer-van der Pol oscillator

2018

Control of nonlinear instabilities in Bessel beams using shaped longitudinal intensity profiles

2017

International audience; We show that tailored longitudinal intensity shaping of a non-diffracting Bessel beam can strongly reduce four wave mixing induced oscillations and stabilize nonlinear propagation at ablation-level intensities

Large-scale inhomogeneities may improve the cosmic concordance of supernovae

2010

We reanalyze the supernovae data from the Union Compilation including the weak lensing effects caused by inhomogeneities. We compute the lensing probability distribution function for each background solution described by the parameters Omega_M, Omega_L and w in the presence of inhomogeneities, approximately modeled with a single-mass population of halos. We then perform a likelihood analysis in the space of FLRW-parameters and compare our results with the standard approach. We find that the inclusion of lensing can move the best-fit model significantly towards the cosmic concordance of the flat LCDM model, improving the agreement with the constraints coming from the cosmic microwave backgro…

Characterizing the Phase Transitions between Stable Equilibrium and Periodic Oscillations in Predator-prey Population Dynamics: A Theoretical Apprais…

2020

Multi-phase patterns with more or less sharp phase transitions, first highlighted in thermodynamics, have progressively revealed having wider relevance, being encountered in various other contexts, for example fluid mechanics, and can even occur in the interactive dynamics in biological populations involving two or more species that share opposite interests, such as predator-prey or parasite-host pairs of species. In the latter, the pattern of abundances of both interacting species usually reaches an equilibrium level which can be either stable or cyclic (with large periodic oscillations in the latter case). Both alternative modes are separated by well-define boundaries and, accordingly, ca…

Working group report: Neutrino physics

2009

This is the report of the neutrino physics working group at WHEPP-X. We summarize the problems selected and discussed at the workshop and the papers which have resulted subsequently.

RELIABILITY OF THE DETECTION OF THE BARYON ACOUSTIC PEAK

2008

The correlation function of the distribution of matter in the universe shows, at large scales, baryon acoustic oscillations, which were imprinted prior to recombination. This feature was first detected in the correlation function of the luminous red galaxies (LRG) of the Sloan Digital Sky Survey (SDSS). The final release (DR7) of the SDSS has been recently made available, and the useful volume is about two times bigger than in the old sample. We present here, for the first time, the redshift space correlation function of this sample at large scales together with that for one shallower, but denser volume-limited subsample drawn from the 2dF redshift survey. We test the reliability of the det…

Experimental Setup with Chaotic and Periodic Excitations for Cell Growth Studies

2020

The paper presents circuits used for excitation living cells to increase their growth rate. The main novelty is the proposal of using chaotic oscillations for the electromagnetic excitation. The research is in a preliminary phase and no conclusions have been yet derived for applications in biotechnology.

Transverse distribution of beam current oscillations of a 14 GHz electron cyclotron resonance ion source

2014

The temporal stability of oxygen ion beams has been studied with the 14 GHz A-ECR at JYFL (University of Jyvaskyla, Department of Physics). A sector Faraday cup was employed to measure the distribution of the beam current oscillations across the beam profile. The spatial and temporal characteristics of two different oscillation “modes” often observed with the JYFL 14 GHz ECRIS are discussed. It was observed that the low frequency oscillations below 200 Hz are distributed almost uniformly. In the high frequency oscillation “mode,” with frequencies >300 Hz at the core of the beam, carrying most of the current, oscillates with smaller amplitude than the peripheral parts of the beam. The result…