128,532 research outputs found
Do Some Stakeholders in Publicly Traded Firms Benefit at the Expense of Others as a Result of Corporate Inversions?
This report examines corporate inversions to determine whether this practice benefits the majority of stakeholders or merely a select few. A sample of firms previously incorporated in the United States that have since undergone inversions is examined to answer this question. Annual stock price returns, stock price volatility, and earnings per share changes from the sample of inversion firms are the main sources of data examined. These results are compared to the S&P 500 and peer firms to determine whether the changes can be attributed to the inversions, or are merely a result of general economic conditions. Supporting topics addressed in this paper include an overview of legislation related to inversions and suggestions to mitigate the negative consequences of inversions. This study shows that there are no observable benefits to shareholder wealth arising from corporate inversions. While there were changes in the data from pre to post inversion, they were not unique to the inversion firms as the same changes were observed in the peer firms. However, the study showed that there is a fundamental difference between inversion firms when compared to the S&P 500
The stability of late-type stars close to the Eddington limit
Super-Eddington luminosities in hydrostatic model atmospheres manifest
themselves by the presence of gas pressure inversions. Such inversions are not
an artifact of the assumption of hydrostatic equilibrium but can also be
present in hydrodynamical model atmospheres. Only for very large mass loss
rates hardly realized in supergiants will the inversions be removed.
Instabilities may, however, still be present in such inversions, which is
investigated for both H-rich and H-deficient late-type supergiant model
atmospheres. A local, non-adiabatic, linear stability analysis reveals that
sound waves can be amplified due to the strong radiative forces. However,
despite the super-Eddington luminosities, the efficiency of the radiative
instabilities is fairly low compared to for early-type stars with growth rates
of .Comment: 11 pages; accepted for publication in Astronomy & Astrophysic
On Quasi-inversions
Given a bounded domain strictly starlike with
respect to we define a quasi-inversion w.r.t. the boundary
We show that the quasi-inversion is bi-Lipschitz w.r.t. the
chordal metric if and only if every "tangent line" of is far away
from the origin. Moreover, the bi-Lipschitz constant tends to when
approaches the unit sphere in a suitable way. For the formulation
of our results we use the concept of the -tangent condition due to F.
W. Gehring and J. V\"ais\"al\"a (Acta Math. 1965). This condition is shown to
be equivalent to the bi-Lipschitz and quasiconformal extension property of what
we call the polar parametrization of . In addition, we show that
the polar parametrization, which is a mapping of the unit sphere onto is bi-Lipschitz if and only if satisfies the -tangent
condition.Comment: 22 pages; 5 figure
Temporal evolution of the Evershed flow in sunspots. II. Physical properties and nature of Evershed clouds
Context: Evershed clouds (ECs) represent the most conspicuous variation of
the Evershed flow in sunspot penumbrae. Aims: We determine the physical
properties of ECs from high spatial and temporal resolution spectropolarimetric
measurements. Methods: The Stokes profiles of four visible and three infrared
spectral lines are subject to inversions based on simple one-component models
as well as more sophisticated realizations of penumbral flux tubes embedded in
a static ambient field (uncombed models). Results: According to the
one-component inversions, the EC phenomenon can be understood as a perturbation
of the magnetic and dynamic configuration of the penumbral filaments along
which these structures move. The uncombed inversions, on the other hand,
suggest that ECs are the result of enhancements in the visibility of penumbral
flux tubes. We conjecture that the enhancements are caused by a perturbation of
the thermodynamic properties of the tubes, rather than by changes in the vector
magnetic field. The feasibility of this mechanism is investigated performing
numerical experiments of thick penumbral tubes in mechanical equilibrium with a
background field. Conclusions: While the one-component inversions confirm many
of the properties indicated by a simple line parameter analysis (Paper I of
this series), we tend to give more credit to the results of the uncombed
inversions because they take into account, at least in an approximate manner,
the fine structure of the penumbra.Comment: Accepted for publication in A&
Multidimensional Matrix Inversions and Elliptic Hypergeometric Series on Root Systems
Multidimensional matrix inversions provide a powerful tool for studying
multiple hypergeometric series. In order to extend this technique to elliptic
hypergeometric series, we present three new multidimensional matrix inversions.
As applications, we obtain a new elliptic Jackson summation, as well as
several quadratic, cubic and quartic summation formulas
A Tonnetz Model for pentachords
This article deals with the construction of surfaces that are suitable for
representing pentachords or 5-pitch segments that are in the same class.
It is a generalization of the well known \"Ottingen-Riemann torus for triads of
neo-Riemannian theories. Two pentachords are near if they differ by a
particular set of contextual inversions and the whole contextual group of
inversions produces a Tiling (Tessellation) by pentagons on the surfaces. A
description of the surfaces as coverings of a particular Tiling is given in the
twelve-tone enharmonic scale case.Comment: 27 pages, 12 figure
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