University of Colorado Boulder

About: University of Colorado Boulder is a education organization based out in Boulder, Colorado, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 48794 authors who have published 115151 publications receiving 5387328 citations. The organization is also known as: CU Boulder & UCB.

Executive Overconfidence and the Slippery Slope to Financial Misreporting

Abstract: A detailed analysis of 49 firms subject to AAERs suggests that approximately one-quarter of the misstatements meet the legal standards of intent. In the remaining three quarters, the initial misstatement reflects an optimistic bias that is not necessarily intentional. Because of the bias, however, in subsequent periods these firms are more likely to be in a position in which they are compelled to intentionally misstate earnings. Overconfident executives are more likely to exhibit an optimistic bias and thus are more likely to start down a slippery slope of growing intentional misstatements. Evidence from a high-tech sample and a larger and more general sample support the overconfidence explanation for this path to misstatements and AAERs.

The Formation of Brown Dwarfs as Ejected Stellar Embryos

Abstract: We conjecture that brown dwarfs are substellar objects because they have been ejected from small newborn multiple systems that have decayed in dynamical interactions. In this view, brown dwarfs are stellar embryos for which the star formation process was aborted before the hydrostatic cores could build up enough mass to eventually start hydrogen burning. The disintegration of a small multiple system is a stochastic process, which can be described only in terms of the half-life of the decay. A stellar embryo competes with its siblings in order to accrete infalling matter, and the one that grows slowest is most likely to be ejected. With better luck, a brown dwarf would therefore have become a normal star. This interpretation of brown dwarfs readily explains the rarity of brown dwarfs as close companions to normal stars, the absence of wide brown dwarf binaries, and the flattening of the low-mass end of the initial mass function. Possible observational tests of this scenario include statistics of brown dwarfs near Class 0 sources and the kinematics of brown dwarfs in star-forming regions, while they still retain a kinematic signature of their expulsion. Because the ejection process limits the amount of gas brought along in a disk, it is predicted that substellar equivalents to the classical T Tauri stars should be rather short-lived.

Monte-Carlo inversion for a global shear-velocity model of the crust and upper mantle

Abstract: SUMMARY We describe a method to invert surface wave dispersion data for a model of shear velocities with uncertainties in the crust and uppermost mantle. The inversion is a multistep process, constrained by a priori information, that culminates in a Markov-chain Monte-Carlo sampling of model space to yield an ensemble of acceptable models at each spatial node. The model is radially anisotropic in the uppermost mantle to an average depth of about 200 km and is isotropic elsewhere. The method is applied on a 2 ◦ × 2 ◦ grid globally to a large data set of fundamental mode surface wave group and phase velocities (Rayleigh group velocity, 16‐200 s; Love group velocity, 16‐150 s; Rayleigh and Love phase velocity, 40‐150 s). The middle of the ensemble (Median Model) defines the estimated model and the half-width of the corridor of models provides the uncertainty estimate. Uncertainty estimates allow the identification of the robust features of the model which, typically, persist only to depths of ∼250 km. We refer to the features that appear in every member of the ensemble of acceptable models as ‘persistent’. Persistent features include sharper images of the variation of oceanic lithosphere and asthenosphere with age, continental roots, extensional tectonic features in the upper mantle, the shallow parts of subducted lithosphere, and improved resolution of radial anisotropy. In particular, we find no compelling evidence for ‘negative anisotropy’ (vsv >v sh) anywhere in the world’s lithosphere.