@article{liu_yang_bondell_martin_2021, title={BAYESIAN INFERENCE IN HIGH-DIMENSIONAL LINEAR MODELS USING AN EMPIRICAL CORRELATION-ADAPTIVE PRIOR}, volume={31}, ISSN={["1996-8507"]}, DOI={10.5705/ss.202019.0133}, abstractNote={In the context of a high-dimensional linear regression model, we propose the use of an empirical correlation-adaptive prior that makes use of information in the observed predictor variable matrix to adaptively address high collinearity, determining if parameters associated with correlated predictors should be shrunk together or kept apart. Under suitable conditions, we prove that this empirical Bayes posterior concentrates around the true sparse parameter at the optimal rate asymptotically. A simplified version of a shotgun stochastic search algorithm is employed to implement the variable selection procedure, and we show, via simulation experiments across different settings and a real-data application, the favorable performance of the proposed method compared to existing methods.}, number={4}, journal={STATISTICA SINICA}, author={Liu, Chang and Yang, Yue and Bondell, Howard and Martin, Ryan}, year={2021}, month={Oct}, pages={2051–2072} }
@article{yang_kneller_2018, title={Neutrino flavor transformation in supernovae as a probe for nonstandard neutrino-scalar interactions}, volume={97}, ISSN={["2470-0029"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85048113006&partnerID=MN8TOARS}, DOI={10.1103/physrevd.97.103018}, abstractNote={We explore the possibility of probing the nonstandard interactions between the neutrino and a hypothetical massive scalar or pseudoscalar via neutrino flavor transformation in supernovae. We find that in ultrarelativistic limit, the effective interaction between the neutrinos does not vanish if neutrinos are Majorana fermions but does vanish if neutrinos are Dirac fermions. The impact of the new neutrino interaction upon the flavor transformation above the neutrinosphere has been calculated in the context of the multi-angle "neutrino bulb model" and we find that the addition of the nonstandard neutrino self-interaction (NSSI) to the ordinary V-A self-interaction between neutrinos is capable of dramatically altering the collective oscillation when its strength is comparable to the standard, V-A, interaction. The effect of flavor-preserving (FP) NSSI is generally to suppress flavor transformation, while the flavor-violating (FV) components are found to promote flavor transformations. The neutrino signal from a Galactic supernova can provide complimentary constraints on scalar/pseudoscalar interactions of neutrinos as well as distinguishing whether the neutrino is a Majorana or Dirac fermion.}, number={10}, journal={PHYSICAL REVIEW D}, author={Yang, Yue and Kneller, James P.}, year={2018}, month={May} }
@article{yang_kneller_2018, title={Neutrino flavour evolution through fluctuating matter}, volume={45}, ISSN={["1361-6471"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85044239930&partnerID=MN8TOARS}, DOI={10.1088/1361-6471/aab0c4}, abstractNote={A neutrino propagating through fluctuating matter can experience large amplitude transitions between its states. Such transitions occur in supernovae and compact object mergers due to turbulent matter profiles and neutrino self-interactions. In this paper we study, both numerically and analytically, three-flavour neutrino transformation through fluctuating matter built from two and three Fourier modes. We find flavor transformation effects which cannot occur with just two flavours. For the case of two Fourier modes we observe the equivalent of "induced transparency" from quantum optics whereby transitions between a given pair of states are suppressed due to the presence of a resonant mode between another pair. When we add a third Fourier mode we find a new effect whereby the third mode can manipulate the transition probabilities of the two mode case so as to force complete transparency or, alternatively, restore "opacity" meaning the perturbative Hamiltonian regains its ability to induce neutrino flavour transitions. In both applications we find analytic solutions are able to match the amplitude and wavenumber of the numerical results to within a few percent. We then consider a case of turbulence and show how the theory can be used to understand the very different response of a neutrino to what appears to be two, almost identical, instances of turbulence.}, number={4}, journal={JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS}, author={Yang, Y. and Kneller, J. P.}, year={2018}, month={Apr} }
@article{yang_kneller_2017, title={GR effects in supernova neutrino flavor transformations}, volume={96}, ISSN={["2470-0029"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85027052291&partnerID=MN8TOARS}, DOI={10.1103/physrevd.96.023009}, abstractNote={The strong gravitational field around a proto-neutron star can modify the neutrino flavor transformations that occur above the neutrinosphere via three General Relativistic (GR) effects: time dilation, energy redshift, and trajectory bending. Depending on the compactness of the central object, the neutrino self-interaction potential is up to three times as large as that without GR principally due to trajectory bending which increases the intersection angles between different neutrino trajectories, and time dilation which changes the fluxes. We determine whether GR effects are important for flavor transformation during the different epochs of a supernova by using multi-angle flavor transformation calculations and consider a density profile and neutrino spectra representative of both the accretion and cooling phases. We find the GR effects are smaller during the accretion phase due to low compactness of the proto-neutron star and merely delay the decoherence; the neutrino bipolar oscillations during the cooling phase are also delayed due to the GR effects but the delay may be more important because the delay occurs at radii where it might alter the nucleosynthesis in the neutrino driven wind.}, number={2}, journal={PHYSICAL REVIEW D}, author={Yang, Yue and Kneller, James P.}, year={2017}, month={Jul} }