Crossover from tunneling to multiphoton ionization of atoms

We present a theory illuminating the cross-over from strong-field tunnelling ionization to weak-field multiphoton ionization in the interaction of a classical laser field with a hydrogen atom. A simple formula is derived in which the ionization amplitude appears as a product of two separate amplitudes. The first describes the initial polarization of the atom by virtual multiphoton absorption and the second the subsequent tunnelling out of the polarized atom. Tunnelling directly from the ground state and multiphoton absorption without tunnelling appear naturally as the limits of the theory

Is There Evidence that Legislative Ambition Matches Development? Evaluating the Factors Influencing Wind Energy Development

Resource /Energy Economics and Policy,

Acclimation to Elevated CO2 Increases Constitutive Glucosinolate Levels of Brassica Plants and Affects the Performance of Specialized Herbivores from Contrasting Feeding Guilds

Plants growing under elevated CO2 concentration may acclimate by modifying chemical traits. Most studies have focused on the effects of environmental change on plant growth and productivity. Potential effects on chemical traits involved in resistance, and the consequences of such effects on plant-insect interactions, have been largely neglected. Here, we evaluated the performance of two Brassica specialist herbivores from contrasting feeding guilds, the leaf-feeding Pieris brassicae and the phloem-feeding Brevicoryne brassicae, in response to potential CO2-mediated changes in primary and major secondary metabolites (glucosinolates) in Brassica oleracea. Plants were exposed to either ambient (400ppm) or elevated (800ppm) CO2 concentrations for 2, 6, or 10weeks. Elevated CO2 did not affect primary metabolites, but significantly increased glucosinolate content. The performance of both herbivores was significantly reduced under elevated CO2 suggesting that CO2-mediated increases in constitutive defense chemistry could benefit plants. However, plants with up-regulated defenses could also be subjected to intensified herbivory by some specialized herbivores, due to a chemically-mediated phagostimulatory effect, as documented here for P. brassicae larvae. Our results highlight the importance of understanding acclimation and responses of plants to the predicted increases in atmospheric CO2 concentrations and the concomitant effects of these responses on the chemically-mediated interactions between plants and specialized herbivore

Tiffs, tosses, and turns:Effects of affective reactivity to interpersonal stressors during the day on nightly sleep

BackgroundSleep has been recognized as an antecedent as well as a consequence of daytime stress. However, less research has compared the role of different stressor types on same-night sleep in the context of daily life. Interpersonal stressors may be particularly important, given that social stressors to elicit greater stress responses than other forms of stressors. This study tested the hypothesis that following days when a person exhibits greater negative affect (NA) reactivity to stressors (versus on days with less NA reactivity), sleep quality will be lower. This link between affective reactivity to stressors and subsequent sleep was expected to be more pronounced for interpersonal stressors versus non-interpersonal stressors.MethodsIn this pre-registered study, 252 adults in British Columbia, Canada (ages 25 to 87y; 68% women; 64% White) completed mobile surveys 5x/day for 14 days to assess daily stressors and NA. Self-reported sleep quality was assessed in morning surveys. Multilevel-models tested daily stressors (interpersonal, non-interpersonal, or no stressors), daily NA (averaged across the day), and their interaction as predictors of subsequent sleep quality, controlling for prior-night sleep quality and sociodemographics.ResultsDaily NA and stressor occurrence independently predicted poorer subsequent sleep quality. Stressor type moderated the relationship between NA and sleep quality, such that this association was stronger for interpersonal compared to non-interpersonal stressors.DiscussionThe findings suggest that encountering interpersonal stressors may be particularly impactful to one’s subsequent sleep. Future studies should consider investigating potential mechanisms that may underlie this association, such as pre-sleep cognitive, emotional, and physiological arousal

Running coupling constants of the Luttinger liquid

Two running coupling constants of the Luttinger liquid are computed in the fermion-fermion and fermion-antifermion channels. Nontrivial scaling laws are found together with Landau poles. The apparent contradiction with the expected vanishing of the beta functions is explained.Comment: Final version, to appear in Phys. Lett.

Strong-field ionization via a high-order Coulomb-corrected strong-field approximation

Signatures of the Coulomb corrections in the photoelectron momentum distribution during laser-induced ionization of atoms or ions in tunneling and multiphoton regimes are investigated analytically in the case of an one-dimensional problem. High-order Coulomb corrected strong-field approximation is applied, where the exact continuum state in the S-matrix is approximated by the eikonal Coulomb-Volkov state including the second-order corrections to the eikonal. Although, without high-order corrections our theory coincides with the known analytical R-matrix (ARM) theory, we propose a simplified procedure for the matrix element derivation. Rather than matching the eikonal Coulomb-Volkov wave function with the bound state as in the ARM-theory to remove the Coulomb singularity, we calculate the matrix element via the saddle-point integration method as by time as well as by coordinate, and in this way avoiding the Coulomb singularity. The momentum shift in the photoelectron momentum distribution with respect to the ARM-theory due to high-order corrections is analyzed for tunneling and multiphoton regimes. The relation of the quantum corrections to the tunneling delay time is discusse

Exact Asymptotic Behaviour of Fermion Correlation Functions in the Massive Thirring Model

We obtain an exact asymptotic expression for the two-point fermion correlation functions in the massive Thirring model (MTM) and show that, for $\beta^2=8\pi$, they reproduce the exactly known corresponding functions of the massless theory, explicitly confirming the irrelevance of the mass term at this point. This result is obtained by using the Coulomb gas representation of the fermionic MTM correlators in the bipolar coordinate system.Comment: To appear in J. Phys. A: Math. Gen. 12 page

1D generalized statistics gas: A gauge theory approach

A field theory with generalized statistics in one space dimension is introduced. The statistics enters the scene through the coupling of the matter fields to a statistical gauge field, as it happens in the Chern-Simons theory in two dimensions. We study the particle-hole excitations and show that the long wave length physics of this model describes a gas obeying the Haldane generalized exclusion statistics. The statistical interaction is found to provide a way to describe the low-T critical properties of one-dimensional non-Fermi liquids.Comment: 8 pages, revte

Equivalent bosonic theory for the massive Thirring model with non-local interaction

We study, through path-integral methods, an extension of the massive Thirring model in which the interaction between currents is non-local. By examining the mass-expansion of the partition function we show that this non-local massive Thirring model is equivalent to a certain non-local extension of the sine-Gordon theory. Thus, we establish a non-local generalization of the famous Coleman's equivalence. We also discuss some possible applications of this result in the context of one-dimensional strongly correlated systems and finite-size Quantum Field Theories.Comment: 15 pages, latex, no figure