arXiv subjects

Ananda Roy

Publications and source records attributed to Ananda Roy.

39 records · Page 3Linked to original sources

arXiv2013

Three-wave mixing with three incoming waves: Signal-Idler Coherent Cancellation and Gain Enhancement in a Parametric Amplifier

Coherent, purely-dispersive three-wave mixing systems in optics and superconducting microwave circuits can be operated as parametric amplifiers, generating from a pump wave at one frequency amplified signal and idler waves at lower frequencies. Here we demonstrate the reciprocal process using a Josephson amplifier in which coherently imposed signal and idler beams up-convert to the pump frequency. For signal and idler beams strong enough to significantly deplete the pump, we show that this reciprocal process ("coherent cancellation") leads to large, phase-sensitive modulation and even enhancement of the amplifier gain, in good agreement with theoretical predictions.

physics.optics↗

arXiv2010

Resonant production of the sterile neutrino dark matter and fine-tunings in the [nu]MSM

The generation of lepton asymmetry below the electroweak scale has a considerable impact on production of dark matter sterile neutrinos. Oscillations or decays of the heavier sterile neutrinos in the neutrino minimal standard model can give rise to the requisite lepton asymmetry, provided the masses of the heavier neutrinos are sufficiently degenerate. We study the renormalization group evolution of the mass difference of these singlet fermions to understand the degree of necessary fine-tuning. We construct an example of the model that can lead to a technically natural realization of this low-energy degeneracy.

hep-ph↗

arXiv2010

Renormalization of masses of sterile neutrinos in the [nu]MSM

The quasi-degeneracy of heavier sterile neutrino masses in the Neutrino Minimal Standard Model ($ν$MSM) facilitates the production of lepton asymmetry below the electroweak scale. The first order loop corrections to this mass-difference has been computed in this work along with a numerical estimate of the contribution.

hep-ph↗