1,017 research outputs found
Monopole equations on 8-manifolds with Spin(7) holonomy
We construct a consistent set of monopole equations on eight-manifolds with
Spin(7) holonomy. These equations are elliptic and admit non-trivial solutions
including all the 4-dimensional Seiberg-Witten solutions as a special case.Comment: 14 pages, LATEX (No figures
Mapping of non-central potentials under point canonical transformations
Motivated by the observation that all known exactly solvable shape invariant
central potentials are inter-related via point canonical transformations, we
develop an algebraic framework to show that a similar mapping procedure is also
exist between a class of non-central potentials. As an illustrative example, we
discuss the inter-relation between the generalized Coulomb and oscillator
systems.Comment: 11 pages article in LaTEX (uses standard article.sty). Please check
http://www1.gantep.edu.tr/~gonul for other studies of Nuclear Physics Group
at University of Gaziante
Zonal Jets as Transport Barriers in Planetary Atmospheres
The connection between transport barriers and potential vorticity (PV)
barriers in PV-conserving flows is investigated with a focus on zonal jets in
planetary atmospheres. A perturbed PV-staircase model is used to illustrate
important concepts. This flow consists of a sequence of narrow eastward and
broad westward zonal jets with a staircase PV structure; the PV-steps are at
the latitudes of the cores of the eastward jets. Numerically simulated
solutions to the quasigeostrophic PV conservation equation in a perturbed
PV-staircase flow are presented. These simulations reveal that both eastward
and westward zonal jets serve as robust meridional transport barriers. The
surprise is that westward jets, across which the background PV gradient
vanishes, serve as robust transport barriers. A theoretical explanation of the
underlying barrier mechanism is provided. It is argued that transport barriers
near the cores of westward zonal jets, across which the background PV gradient
is small, are found in Jupiter's midlatitude weather layer and in the Earth's
summer hemisphere subtropical stratosphere.Comment: Accepted for publication in JA
Maternal metabolic factors during pregnancy predict early childhood growth trajectories and obesity risk: the CANDLE Study.
BackgroundWe investigated the individual and additive effects of three modifiable maternal metabolic factors, including pre-pregnancy overweight/obesity, gestational weight gain (GWG), and gestational diabetes mellitus (GDM), on early childhood growth trajectories and obesity risk.MethodsA total of 1425 mother-offspring dyads (953 black and 472 white) from a longitudinal birth cohort were included in this study. Latent class growth modeling was performed to identify the trajectories of body mass index (BMI) from birth to 4 years in children. Poisson regression models were used to examine the associations between the maternal metabolic risk factors and child BMI trajectories and obesity risk at 4 years.ResultsWe identified three discrete BMI trajectory groups, characterized as rising-high-BMI (12.6%), moderate-BMI (61.0%), or low-BMI (26.4%) growth. Both maternal pre-pregnancy obesity (adjusted relative risk [adjRR] = 1.96; 95% confidence interval [CI]: 1.36-2.83) and excessive GWG (adjRR = 1.71, 95% CI: 1.13-2.58) were significantly associated with the rising-high-BMI trajectory, as manifested by rapid weight gain during infancy and a stable but high BMI until 4 years. All three maternal metabolic indices were significantly associated with childhood obesity at age 4 years (adjRR for pre-pregnancy obesity = 2.24, 95% CI: 1.62-3.10; adjRR for excessive GWG = 1.46, 95% CI: 1.01-2.09; and adjRR for GDM = 2.14, 95% = 1.47-3.12). In addition, risk of rising-high BMI trajectory or obesity at age 4 years was stronger among mothers with more than one metabolic risk factor. We did not observe any difference in these associations by race.ConclusionMaternal pre-pregnancy obesity, excessive GWG, and GDM individually and jointly predict rapid growth and obesity at age 4 years in offspring, regardless of race. Interventions targeting maternal obesity and metabolism may prevent or slow the rate of development of childhood obesity
Any -state solutions of the Hulth\'en potential by the asymptotic iteration method
In this article, we present the analytical solution of the radial
Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of
the asymptotic iteration method by using an approximation to the centrifugal
potential for any states. We obtain the energy eigenvalues and the
corresponding eigenfunctions for different screening parameters. The wave
functions are physical and energy eigenvalues are in good agreement with the
results obtained by other methods for different values. In order to
demonstrate this, the results of the asymptotic iteration method are compared
with the results of the supersymmetry, the numerical integration, the
variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur
- …