1,640 research outputs found
Mapping the CMB II: the second flight of the QMAP experiment
We report the results from the second flight of QMAP, an experiment to map
the cosmic microwave background near the North Celestial Pole. We present maps
of the sky at 31 and 42 GHz as well as a measurement of the angular power
spectrum covering the l-range 40-200. Anisotropy is detected at about 20 sigma
and is in agreement with previous results at these angular scales. We also
report details of the data reduction and analysis techniques which were used
for both flights of QMAP.Comment: 4 pages, with 5 figures included. Submitted to ApJL. Window functions
and color figures are available at
http://pupgg.princeton.edu/~cmb/welcome.htm
Daily torpor: When heart and brain go cold - Nonlinear cardiac dynamics in the seasonal heterothermic Djungarian hamster
Djungarian hamsters (Phodopus sungorus) acclimated to short photoperiod display episodes of spontaneous daily torpor with metabolic rate depressed by ∼70%, body temperature (
Galactic contamination in the QMAP experiment
We quantify the level of foreground contamination in the QMAP Cosmic
Microwave Background (CMB) data with two objectives: (a) measuring the level to
which the QMAP power spectrum measurements need to be corrected for foregrounds
and (b) using this data set to further refine current foreground models. We
cross-correlate the QMAP data with a variety of foreground templates. The 30
GHz Ka-band data is found to be significantly correlated with the Haslam 408
MHz and Reich and Reich 1420 MHz synchrotron maps, but not with the Diffuse
Infrared Background Experiment (DIRBE) 240, 140 and 100 micron maps or the
Wisconsin H-Alpha Mapper (WHAM) survey. The 40 GHz Q-band has no significant
template correlations. We discuss the constraints that this places on
synchrotron, free-free and dust emission. We also reanalyze the
foreground-cleaned Ka-band data and find that the two band power measurements
are lowered by 2.3% and 1.3%, respectively.Comment: 4 ApJL pages, including 4 figs. Color figures and data at
http://www.hep.upenn.edu/~angelica/foreground.html#qmap or from
[email protected]
SUSY approach to Pauli Hamiltonians with an axial symmetry
A two-dimensional Pauli Hamiltonian describing the interaction of a neutral
spin-1/2 particle with a magnetic field having axial and second order
symmetries, is considered. After separation of variables, the one-dimensional
matrix Hamiltonian is analyzed from the point of view of supersymmetric quantum
mechanics. Attention is paid to the discrete symmetries of the Hamiltonian and
also to the Hamiltonian hierarchies generated by intertwining operators. The
spectrum is studied by means of the associated matrix shape-invariance. The
relation between the intertwining operators and the second order symmetries is
established and the full set of ladder operators that complete the dynamical
algebra is constructed.Comment: 18 pages, 3 figure
Superintegrability and higher order polynomial algebras II
In an earlier article, we presented a method to obtain integrals of motion
and polynomial algebras for a class of two-dimensional superintegrable systems
from creation and annihilation operators. We discuss the general case and
present its polynomial algebra. We will show how this polynomial algebra can be
directly realized as a deformed oscillator algebra. This particular algebraic
structure allows to find the unitary representations and the corresponding
energy spectrum. We apply this construction to a family of caged anisotropic
oscillators. The method can be used to generate new superintegrable systems
with higher order integrals. We obtain new superintegrable systems involving
the fourth Painleve transcendent and present their integrals of motion and
polynomial algebras.Comment: 11 page
An infinite family of superintegrable systems from higher order ladder operators and supersymmetry
We will discuss how we can obtain new quantum superintegrable Hamiltonians
allowing the separation of variables in Cartesian coordinates with higher order
integrals of motion from ladder operators. We will discuss also how higher
order supersymmetric quantum mechanics can be used to obtain systems with
higher order ladder operators and their polynomial Heisenberg algebra. We will
present a new family of superintegrable systems involving the fifth Painleve
transcendent which possess fourth order ladder operators constructed from
second order supersymmetric quantum mechanics. We present the polynomial
algebra of this family of superintegrable systems.Comment: 8 pages, presented at ICGTMP 28, accepted for j.conf.serie
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