274 research outputs found
Register of Australian herbage plant cultivars. B. Legumes. 1. Clover (d) Trifolium subterraneum L. var. subterraneum (Katz. et Morley) Zohary and Heller (subterranean clover) cv. York
On the energy growth of some periodically driven quantum systems with shrinking gaps in the spectrum
We consider quantum Hamiltonians of the form H(t)=H+V(t) where the spectrum
of H is semibounded and discrete, and the eigenvalues behave as E_n~n^\alpha,
with 0<\alpha<1. In particular, the gaps between successive eigenvalues decay
as n^{\alpha-1}. V(t) is supposed to be periodic, bounded, continuously
differentiable in the strong sense and such that the matrix entries with
respect to the spectral decomposition of H obey the estimate
|V(t)_{m,n}|0,
p>=1 and \gamma=(1-\alpha)/2. We show that the energy diffusion exponent can be
arbitrarily small provided p is sufficiently large and \epsilon is small
enough. More precisely, for any initial condition \Psi\in Dom(H^{1/2}), the
diffusion of energy is bounded from above as _\Psi(t)=O(t^\sigma) where
\sigma=\alpha/(2\ceil{p-1}\gamma-1/2). As an application we consider the
Hamiltonian H(t)=|p|^\alpha+\epsilon*v(\theta,t) on L^2(S^1,d\theta) which was
discussed earlier in the literature by Howland
On Fourier transforms of radial functions and distributions
We find a formula that relates the Fourier transform of a radial function on
with the Fourier transform of the same function defined on
. This formula enables one to explicitly calculate the
Fourier transform of any radial function in any dimension, provided one
knows the Fourier transform of the one-dimensional function and
the two-dimensional function . We prove analogous
results for radial tempered distributions.Comment: 12 page
The role and uses of antibodies in COVID-19 infections: a living review
Coronavirus disease 2019 has generated a rapidly evolving field of research, with the global scientific community striving for solutions to the current pandemic. Characterizing humoral responses towards SARS-CoV-2, as well as closely related strains, will help determine whether antibodies are central to infection control, and aid the design of therapeutics and vaccine candidates. This review outlines the major aspects of SARS-CoV-2-specific antibody research to date, with a focus on the various prophylactic and therapeutic uses of antibodies to alleviate disease in addition to the potential of cross-reactive therapies and the implications of long-term immunity
Identified particles in Au+Au collisions at sqrt{s_NN} = 200 GeV
The yields of identified particles have been measured at RHIC for Au+Au
collisions at sqrt{s_NN} = 200 GeV using the PHOBOS spectrometer. The ratios of
antiparticle to particle yields near mid-rapidity are presented. The first
measurements of the invariant yields of charged pions, kaons and protons at
very low transverse momenta are also shown.Comment: 4 pages, 4 figures, Contribution to Quark Matter 2002, Nantes,
France, July 200
Thermal Density Functional Theory in Context
This chapter introduces thermal density functional theory, starting from the
ground-state theory and assuming a background in quantum mechanics and
statistical mechanics. We review the foundations of density functional theory
(DFT) by illustrating some of its key reformulations. The basics of DFT for
thermal ensembles are explained in this context, as are tools useful for
analysis and development of approximations. We close by discussing some key
ideas relating thermal DFT and the ground state. This review emphasizes thermal
DFT's strengths as a consistent and general framework.Comment: Submitted to Spring Verlag as chapter in "Computational Challenges in
Warm Dense Matter", F. Graziani et al. ed
Universal Behavior of Charged Particle Production in Heavy Ion Collisions
The PHOBOS experiment at RHIC has measured the multiplicity of primary
charged particles as a function of centrality and pseudorapidity in Au+Au
collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV. Two kinds of universal
behavior are observed in charged particle production in heavy ion collisions.
The first is that forward particle production, over a range of energies,
follows a universal limiting curve with a non-trivial centrality dependence.
The second arises from comparisons with pp/pbar-p and e+e- data.
N_tot/(N_part/2) in nuclear collisions at high energy scales with sqrt(s) in a
similar way as N_tot in e+e- collisions and has a very weak centrality
dependence. This feature may be related to a reduction in the leading particle
effect due to the multiple collisions suffered per participant in heavy ion
collisions.Comment: 4 Pages, 5 Figures, contributed to the Proceedings of Quark Matter
2002, Nantes, France, 18-24 July 200
Pulsations and eclipse-time analysis of HW Vir
We analysed recent K2 data of the short-period eclipsing binary system HW Vir, which consists of a hot subdwarf-B type primary with an M-dwarf companion. We determined the mid-times of eclipses, calculated O–C diagrams, and an average shift of the secondary minimum. Our results show that the orbital period is stable within the errors over the course of the 70 days of observations. Interestingly, the offset from mid-orbital phase between the primary and the secondary eclipses is found to be 1.62 s. If the shift is explained solely by light-travel time, the mass of the sdB primary must be 0.26 M⊙, which is too low for the star to be core-helium burning. However, we argue that this result is unlikely to be correct and that a number of effects caused by the relative sizes of the stars conspire to reduce the effective light-travel time measurement. After removing the flux variation caused by the orbit, we calculated the amplitude spectrum to search for pulsations. The spectrum clearly shows periodic signal from close to the orbital frequency up to 4600 µHz, with the majority of peaks found below 2600 µHz. The amplitudes are below 0.1 part-per-thousand, too low to be detected with ground-based photometry. Thus, the high-precision data from the Kepler spacecraft has revealed that the primary of the HW Vir system is a pulsating sdBV star. We argue that the pulsation spectrum of the primary in HW Vir differs from that in other sdB stars due to its relatively fast rotation that is (nearly) phase-locked with the orbit
Recent Results from PHOBOS at RHIC
The PHOBOS experiment at RHIC has recorded measurements for Au-Au collisions
spanning nucleon-nucleon center-of-mass energies from 19.6 GeV to 200 GeV.
Global observables such as elliptic flow and charged particle multiplicity
provide important constraints on model predictions that characterize the state
of matter produced in these collisions. The nearly 4 pi acceptance of the
PHOBOS experiment provides excellent coverage for complete flow and
multiplicity measurements. Results including beam energy and centrality
dependencies are presented and compared to elementary systems.Comment: 4 pages, 4 figures, proceedings from PANIC02 in Osaka, Japa
Global Observations from PHOBOS
Particle production in Au+Au collisions has been measured in the PHOBOS
experiment at RHIC for a range of collision energies. Three empirical
observations have emerged from this dataset which require theoretical
examination. First, there is clear evidence of limiting fragmentation. Namely,
particle production in central Au+Au collisions, when expressed as
(), becomes energy independent at high energy for a
broad region of around . This energy-independent region grows
with energy, allowing only a limited region (if any) of longitudinal
boost-invariance. Second, there is a striking similarity between particle
production in e+e- and Au+Au collisions (scaled by the number of participating
nucleon pairs). Both the total number of produced particles and the
longitudinal distribution of produced particles are approximately the same in
e+e- and in scaled Au+Au. This observation was not predicted and has not been
explained. Finally, particle production has been found to scale approximately
with the number of participating nucleon pairs for . This scaling
occurs both for the total multiplicity and for high \pT particles (3 <\pT<
4.5 GeV/c).Comment: QM2002 plenary talk, 10 pages, 11 figure
- …