18,407 research outputs found
Mutual Fund Expense Disclosures: A Behavioral Perspective
Mutual funds have enjoyed phenomenal growth with their numbers exceeding the number of public companies and their assets aggregating in excess of $9 trillion. Increasingly they are the investment instrument of choice by the proverbial widows, widowers and orphans, and a few school teachers are included as well. But how are best can that choice be one that is not only informed but informed in a way more likely to elicit a wise decision? This paper examines from a behavioral perspective how regulation can best disclose information related to two key factors for investors to compare competing mutual funds: fund returns and fund expenses. Our analysis reflects that the current disclosure process is deficient because it fails to reflect the insights of research on judgment and decision making, and particularly the need to distinguish between the availability of information and its processability by its user. The message of our article is straightforward: if regulators adhered to the insights provided by our paper, not only investors, but also the fund\u27s directors, would be greatly empowered so that better returns and lower costs could be expected
Quadrupole moment of a magnetically confined mountain on an accreting neutron star: effect of the equation of state
Magnetically confined mountains on accreting neutron stars are promising
sources of continuous-wave gravitational radiation and are currently the
targets of directed searches with long-baseline detectors like the Laser
Interferometer Gravitational Wave Observatory (LIGO). In this paper, previous
ideal-magnetohydrodynamic models of isothermal mountains are generalized to a
range of physically motivated, adiabatic equations of state. It is found that
the mass ellipticity drops substantially, from \epsilon ~ 3e-4 (isothermal) to
\epsilon ~ 9e-7 (non-relativistic degenerate neutrons), 6e-8 (relativistic
degenerate electrons) and 1e-8 (non-relativistic degenerate electrons)
(assuming a magnetic field of 3e12 G at birth). The characteristic mass M_{c}
at which the magnetic dipole moment halves from its initial value is also
modified, from M_{c}/M_{\sun} ~ 5e-4 (isothermal) to M_{c}/M_{\sun} ~ 2e-6,
1e-7, and 3e-8 for the above three equations of state, respectively. Similar
results are obtained for a realistic, piecewise-polytropic nuclear equation of
state. The adiabatic models are consistent with current LIGO upper limits,
unlike the isothermal models. Updated estimates of gravitational-wave
detectability are made. Monte Carlo simulations of the spin distribution of
accreting millisecond pulsars including gravitational-wave stalling agree
better with observations for certain adiabatic equations of state, implying
that X-ray spin measurements can probe the equation of state when coupled with
magnetic mountain models.Comment: 20 pages, 15 figures, to be published in MNRA
Empirical Traffic Data and Their Implications for Traffic Modeling
From single vehicle data a number of new empirical results about the temporal
evolution, correlation, and density-dependence of macroscopic traffic
quantities have been determined. These have relevant implications for traffic
modeling and allow to test existing traffic models.Comment: For related work see
http://www.theo2.physik.uni-stuttgart.de/helbing.htm
Generalized Wannier functions: a comparison of molecular electric dipole polarizabilities
Localized Wannier functions provide an efficient and intuitive means by which
to compute dielectric properties from first principles. They are most commonly
constructed in a post-processing step, following total-energy minimization.
Nonorthogonal generalized Wannier functions (NGWFs) [Skylaris et al., Phys.
Rev. B 66, 035119 11 (2002); Skylaris et al., J. Chem. Phys. 122, 084119
(2005)] may also be optimized in situ, in the process of solving for the
ground-state density. We explore the relationship between NGWFs and
orthonormal, maximally localized Wannier functions (MLWFs) [Marzari and
Vanderbilt, Phys. Rev. B 56, 12847 (1997); Souza, Marzari, and Vanderbilt,
ibid. 65, 035109 (2001)], demonstrating that NGWFs may be used to compute
electric dipole polarizabilities efficiently, with no necessity for
post-processing optimization, and with an accuracy comparable to MLWFs.Comment: 5 pages, 1 figure. This version matches that accepted for Physical
Review B on 4th May 201
Ligand Discrimination in Myoglobin from Linear-Scaling DFT+U
Myoglobin modulates the binding of diatomic molecules to its heme group via
hydrogen-bonding and steric interactions with neighboring residues, and is an
important benchmark for computational studies of biomolecules. We have
performed calculations on the heme binding site and a significant proportion of
the protein environment (more than 1000 atoms) using linear-scaling density
functional theory and the DFT+U method to correct for self-interaction errors
associated with localized 3d states. We confirm both the hydrogen-bonding
nature of the discrimination effect (3.6 kcal/mol) and assumptions that the
relative strain energy stored in the protein is low (less than 1 kcal/mol). Our
calculations significantly widen the scope for tackling problems in drug design
and enzymology, especially in cases where electron localization, allostery or
long-ranged polarization influence ligand binding and reaction.Comment: 15 pages, 3 figures. Supplementary material 8 pages, 3 figures. This
version matches that accepted for J. Phys. Chem. Lett. on 10th May 201
Gravitational waves from an accreting neutron star with a magnetic mountain
We calculate the amplitude of gravitational waves from a neutron star accreting symmetrically at its magnetic poles. The magnetic field, which is compressed into an equatorial belt during accretion, confines accreted matter in a mountain at the magnetic pole, producing gravitational waves. We compute hydromagnetic equilibria and the corresponding quadrupole moment as a function of the accreted mass, Ma, finding the polarization- and orientation- averaged wave strain at Earth to be h_c = 6.3 × 10^(–25)(M_a/10^(–5)M_☉)(ƒ/0.6kHz)^2(d/1kpc)^(–1) for a range of conditions, where ƒ is the wave frequency and d is the distance to the source. This is ~ 10^2 times greater than previous estimates, which failed to treat the mass-flux distribution self-consistently with respect to flux-freezin
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