25,344 research outputs found
USING LAND EQUITY TO PROVIDE A RETIREMENT INCOME
Many retiring farmers will need to use their land equity to provide a retirement income. Based on a present value analysis, retiring farmers may either decide to sell or lease their land. The analysis is needed because taxes, liability issues, and goals of the farmer complicate the decision.retirement, land equity, Consumer/Household Economics, Land Economics/Use,
Transition matrices for symmetric and quasisymmetric Hall-Littlewood polynomials
We introduce explicit combinatorial interpretations for the coefficients in
some of the transition matrices relating to skew Hall-Littlewood polynomials
P_lambda/mu(x;t) and Hivert's quasisymmetric Hall-Littlewood polynomials
G_gamma(x;t). More specifically, we provide: 1) the G-expansions of the
Hall-Littlewood polynomials P_lambda, the monomial quasisymmetric polynomials
M_alpha, the quasisymmetric Schur polynomials S_alpha, and the peak
quasisymmetric functions K_alpha; 2) an expansion of P_lambda/mu in terms of
the F_alpha's. The F-expansion of P_lambda/mu is facilitated by introducing
starred tableaux.Comment: 28 pages; added brief discussion of the Hall-Littlewood Q', typos
corrected, added references in response to referee suggestion
Coulomb drag between helical edge states
We theoretically investigate the Coulomb drag between the edge states of two
quantum spin Hall systems. Using an interacting theory of the one-dimensional
helical edge modes, we show that the drag vanishes at second order in the
inter-edge interaction, where it is typically finite in other systems, due to
the absence of backscattering within the edges. However, in the presence of a
small external magnetic field the drag is finite and scales as the fourth power
of the magnetic field, a behavior that sharply distinguishes it from other
systems. We obtain the temperature dependence of the drag for regimes of both
linear and quadratic edge dispersion in the presence of a finite field.Comment: 4 pages, 3 figure
Dissipation-Scale Turbulence in the Solar Wind
We present a cascade model for turbulence in weakly collisional plasmas that
follows the nonlinear cascade of energy from the large scales of driving in the
MHD regime to the small scales of the kinetic Alfven wave regime where the
turbulence is dissipated by kinetic processes. Steady-state solutions of the
model for the slow solar wind yield three conclusions: (1) beyond the observed
break in the magnetic energy spectrum, one expects an exponential cut-off; (2)
the widely held interpretation that this dissipation range obeys power-law
behavior is an artifact of instrumental sensitivity limitations; and, (3) over
the range of parameters relevant to the solar wind, the observed variation of
dissipation range spectral indices from -2 to -4 is naturally explained by the
varying effectiveness of Landau damping, from an undamped prediction of -7/3 to
a strongly damped index around -4.Comment: 6 pages, 2 figures, accepted for publication in AIP Conference
Proceedings on "Turbulence and Nonlinear Processes in Astrophysical Plasmas
Rotationally Modulated X-ray Emission from T Tauri Stars
We have modelled the rotational modulation of X-ray emission from T Tauri
stars assuming that they have isothermal, magnetically confined coronae. By
extrapolating surface magnetograms we find that T Tauri coronae are compact and
clumpy, such that rotational modulation arises from X-ray emitting regions
being eclipsed as the star rotates. Emitting regions are close to the stellar
surface and inhomogeneously distributed about the star. However some regions of
the stellar surface, which contain wind bearing open field lines, are dark in
X-rays. From simulated X-ray light curves, obtained using stellar parameters
from the Chandra Orion Ultradeep Project, we calculate X-ray periods and make
comparisons with optically determined rotation periods. We find that X-ray
periods are typically equal to, or are half of, the optical periods. Further,
we find that X-ray periods are dependent upon the stellar inclination, but that
the ratio of X-ray to optical period is independent of stellar mass and radius.Comment: 10 pages, 8 figures, accepted for publication in MNRA
Inflating magnetically charged braneworlds
Numerical solutions of Einstein, scalar, and gauge field equations are found
for static and inflating defects in a higher-dimensional spacetime. The defects
have -dimensional core and magnetic monopole configuration in
extra dimensions. For symmetry-breaking scale below the critical value
, the defects are characterized by a flat worldsheet geometry and
asymptotically flat extra dimensions. The critical scale is comparable
to the higher-dimensional Planck scale and has some dependence on the gauge and
scalar couplings. For , the extra dimensions degenerate into a
`cigar', and for all static solutions are singular. The
singularity can be removed if the requirement of staticity is relaxed and
defect cores are allowed to inflate. The inflating solutions have de Sitter
worldsheets and cigar geometry in the extra dimensions. Exact analytic
solutions describing the asymptotic behavior of these inflating monopoles are
found and the parameter space of these solutions is analyzed.Comment: 35 pages, revtex, 18 eps figure
A new measurement of the cosmic ray energy spectrum between 3 x 10 to the 15th power eV and 3 x 10 to the 16th power eV
A new Cerenkov photon density spectrum measurement is reported. The derivation of the primary cosmic ray energy spectrum for energies from 3x10 to the 15th power eV to 3x10 to the 16th power eV are presented
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