Resonant leptogenesis

We study the scenario of thermal leptogenesis in which the leptonic asymmetries are resonantly enhanced through the mixing of nearly degenerate heavy Majorana neutrinos that have mass differences comparable to their decay widths. Field-theoretic issues arising from the proper subtraction of real intermediate states from the lepton-number-violating scattering processes are addressed in connection with an earlier developed resummation approach to unstable particle mixing in decay amplitudes. The pertinent Boltzmann equations are numerically solved after the enhanced heavy-neutrino self-energy effects on scatterings and the dominant gauge-mediated collision terms are included. We show that resonant leptogenesis can be realized with heavy Majorana neutrinos even as light as ∼1 TeV, in complete accordance with the current solar and atmospheric neutrino data.     

Resonant holography

We present a method of enhancing the diffraction efficiency of a hologram by placing it inside a resonant optical cavity. The diffraction efficiency improves on account of the multiple passes that the incident light undergoes inside the optical cavity. The resonance condition in this case turns out to involve both mirror reflectivity and the optical path length inside the cavity. Experimental results for a resonantly enhanced angle-multiplexed holographic memory and an optical three-port element are shown.     

Resonant nucleation

We investigate the role played by fast quenching on the decay of metastable (or false vacuum) states. Instead of the exponentially slow decay rate per unit volume, Gamma(HN) approximately exp([-E(b)/k(B)T] (E(b) is the free energy of the critical bubble), predicted by homogeneous nucleation theory, we show that under fast enough quenching the decay rate is a power law Gamma(RN) approximately [E(b)/k(B)T](-B), where B is weakly sensitive to the temperature. For a range of parameters, large-amplitude oscillations about the metastable state trigger the resonant emergence of coherent subcritical configurations. Decay mechanisms for different E(b) are proposed and illustrated in a (2+1)-dimensional scalar field model.     

Resonant scattering of solitons

We study the scattering of solitons in the nonlinear Schr?dinger equation on local inhomogeneities which may give rise to resonant transmission and reflection. In both cases, we derive resonance conditions for the soliton's velocity. The analytical predictions are tested numerically in regimes characterized by various time scales. Special attention is paid to intermode interactions and their effect on coherence, decoherence, and dephasing of plane-wave modes which build up the soliton.     

Resonant freak microwaves

The Helmholtz equation describing transverse magnetic modes in a closed flat microwave resonator with 60 randomly distributed discs is numerically solved. At lower frequencies, the calculated wave intensity spatially distributed obeys the universal Porter-Thomas form if localized modes are excluded. A superposition of resonant modes is shown to lead to rare events of extreme intensities (freak waves) at localized “hot spots”. The temporally distributed intensity of such a superposition at the center of a hot spot also follows the Porter-Thomas form. Branched modes are found at higher frequencies. The results bear resemblance to recent experiments reported in an open cavity.     

Resonant quasi-resonant solitons

Propagation of an optical pulse in a set of transitions created by simple Zeeman splitting is investigated. It is shown that resonant and nonresonant circularly polarized components repel one another, while a coupled soliton state can be formed only between quasi-resonant components whose planes of polarization rotate in opposite directions.     

Resonant laser tunnelling

We propose an experiment involving a gaussian laser tunneling through a twin barrier dielectricstructure. Of particular interest are the conditions upon the incident angle for resonance to occur. Weprovide some numerical calculations for a particular choice of laser wave length and dielectricrefractive index which confirm our expectations.     

Resonant control of solitons

It is shown that the effect of “scattering on resonance” can be used to control envelope solitons in the driven nonlinear Schrödinger equation. The control occurs by the frequency modulated driving with multiple crossing of the resonant frequency of the soliton.     

Resonant helical divertor

A concept for a helical divertor is proposed, which utilizes a resonance effect, and reduces the required divertor currents to a small fraction (typically 10^-2) of the plasma current. This divertor should have a larger screening efficiency than the poloidal field divertor, and could operate with divertor coils outside the vacuum vessel or the blanket.     

Resonant Mechanism of Solar-Terrestrial Relationships

The present paper studies the resonant mechanism of solar-terrestrial relationships and their influence on the state of individual systems of the human organism. The level of statistical correlation between the characteristics of the human cardiovascular system and the brain activity and the fundamental modes of circumterrestrial resonators are numerically evaluated.     

Resonant inversion of tunneling magnetoresistance

Resonant tunneling via localized states in the barrier can invert magnetoresistance in magnetic tunnel junctions. Experiments performed on electrodeposited Ni/NiO/Co nanojunctions of area smaller than 0.01 microm(2) show that both positive and negative values of magnetoresistance are possible. Calculations based on Landauer-Büttiker theory explain this behavior in terms of disorder-driven statistical variations in magnetoresistance with a finite probability of inversion due to resonant tunneling.     

Resonant production of topological defects

We describe a novel phenomenon in which vortices are produced due to resonant oscillations of a scalar field which is driven by a periodically varying temperature T, with T remaining much below the critical temperature T(c). Also, in a rapid heating of a localized region to a temperature below T(c), far separated vortex and antivortex can form. We compare our results with recent models of defect production during reheating after inflation. We also discuss possible experimental tests of our predictions of topological defect production without ever going through a phase transition.     

Resonant tunneling properties of heterostructures

A general theory of resonance tunneling in planar structures, independent of the detailed form of the “well”, is developed. The transmission probability versus energy is Lorentzian, near each quasi-local level, with a width that is simply related to the lifetime for escape from the local state, the wave-packet transit time, and the dynamical response time. The charge-accumulation effect is estimated.     

Resonant Interactions of Vector Breathers

JETP Letters - We study vector solitons propagating on an unstable constant background (vector breathers) theoretically in the framework of the focusing two-component one-dimensional nonlinear...     

Acoustic Interpretation of Resonant Voice

Resonant voice, often described in terms of vibratory sensations in the face, is investigated acoustically by calculating vocal tract inertance. It appears that the ease of production and vibrancy of resonant voice depends more on lowering phonation threshold pressure than on tissue or air resonance in or around the face. Phonation threshold pressure is lowered by increasing air column inertance in the laryngeal vestibule. The fact that the sensations are felt in the face is an indication of effective conversion of aerodynamic energy to acoustic energy, rather than sound resonation in the sinuses or the nasal airways.