65 research outputs found
Stock Market Speculation: Spontaneous Symmetry Breaking of Economic Valuation
Firm foundation theory estimates a security's firm fundamental value based on
four determinants: expected growth rate, expected dividend payout, the market
interest rate and the degree of risk. In contrast, other views of
decision-making in the stock market, using alternatives such as human
psychology and behavior, bounded rationality, agent-based modeling and
evolutionary game theory, expound that speculative and crowd behavior of
investors may play a major role in shaping market prices. Here, we propose that
the two views refer to two classes of companies connected through a ``phase
transition''. Our theory is based on 1) the identification of the fundamental
parity symmetry of prices (), which results from the relative
direction of payment flux compared to commodity flux and 2) the observation
that a company's risk-adjusted growth rate discounted by the market interest
rate behaves as a control parameter for the observable price. We find a
critical value of this control parameter at which a spontaneous
symmetry-breaking of prices occurs, leading to a spontaneous valuation in
absence of earnings, similarly to the emergence of a spontaneous magnetization
in Ising models in absence of a magnetic field. The low growth rate phase is
described by the firm foundation theory while the large growth rate phase is
the regime of speculation and crowd behavior. In practice, while large
``finite-time horizon'' effects round off the predicted singularities, our
symmetry-breaking speculation theory accounts for the apparent over-pricing and
the high volatility of fast growing companies on the stock markets.Comment: 23 pages, 10 figure
Teachers as leaders in a knowledge society: encouraging signs of a new professionalism
[Abstract]: Challenges confronting schools worldwide are greater than ever,and, likewise, many teachers possess capabilities, talents, and formal credentials more sophisticated than ever. However, the responsibility and authority accorded
to teachers have not grown significantly, nor has the image of teaching as a profession advanced significantly. The question becomes, what are the implications for the image and status of the teaching profession as the concept of knowledge society takes a firm hold in the industrialized world? This article addresses the philosophical underpinnings of teacher leadership manifested in case studies where schools sought to achieve the generation of new knowledge as part of a process of whole-school revitalization. Specifically, this article reports on Australian research that has illuminated the work of teacher leaders engaged in the IDEAS project, a joint school revitalization initiative of the University
of Southern Queensland and the Queensland Department of Education and the Arts
Lyapunov exponents and transport in the Zhang model of Self-Organized Criticality
We discuss the role played by the Lyapunov exponents in the dynamics of
Zhang's model of Self-Organized Criticality. We show that a large part of the
spectrum (slowest modes) is associated with the energy transpor in the lattice.
In particular, we give bounds on the first negative Lyapunov exponent in terms
of the energy flux dissipated at the boundaries per unit of time. We then
establish an explicit formula for the transport modes that appear as diffusion
modes in a landscape where the metric is given by the density of active sites.
We use a finite size scaling ansatz for the Lyapunov spectrum and relate the
scaling exponent to the scaling of quantities like avalanche size, duration,
density of active sites, etc ...Comment: 33 pages, 6 figures, 1 table (to appear
Young Stellar Clusters Containing Massive Young Stellar Objects in the VVV Survey
This is an author-created, un-copyedited version of an article published in The Astronomical Journal. IOP Publishing is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at: at doi: https://doi.org/10.3847/0004-6256/152/3/74. © 2016. The American Astronomical Society. All rights reserved. IOPScience PublishingThe purpose of this research is to study the connection of global properties of eight young stellar clusters projected in the Vista Variables in the Via Lactea (VVV) ESO Large Public Survey disk area and their young stellar object population. The analysis in based on the combination of spectroscopic parallax-based reddening and distance determinations with main sequence and pre-main sequence ishochrone fitting to determine the basic parameters (reddening, age, distance) of the sample clusters. The lower mass limit estimations show that all clusters are low or intermediate mass (between 110 and 1800 Mo), the slope Gamma of the obtained present-day mass functions of the clusters is close to the Kroupa initial mass function. On the other hand, the young stellar objects in the surrounding cluster's fields are classified by low resolution spectra, spectral energy distribution fit with theoretical predictions, and variability, taking advantage of multi-epoch VVV observations. All spectroscopically confirmed young stellar objects (except one) are found to be massive (more than 8 Mo). Using VVV and GLIMPSE color-color cuts we have selected a large number of new young stellar object candidates, which are checked for variability and 57% are found to show at least low-amplitude variations. In few cases it was possible to distinguish between YSO and AGB classification on the basis of the light curves.Peer reviewedFinal Accepted Versio
Mantle wedge hydration in Nicaragua from Local Earthquake Tomography
The continental margin of Nicaragua and Costa Rica is characterized by significant lateral changes from north to south such as a decreasing dip of the slab, a decreasing magma production and a shift in the volcanic front. To investigate this transition, a joint on- and offshore local earthquake tomography was performed. Low P-wave velocities and high Vp/Vs ratios, indicative for hydration, were found in the upper-mantle and lowermost crust beneath the Sandino Basin. The mantle wedge hydration can be estimated to 2.5 wt. per cent beneath south Nicaragua. In contrast, the mantle wedge beneath north Costa Rica is weakly or not hydrated. The hydration leads to a local gap in the seismicity in Nicaragua. The lateral transition between the hydrated and non-hydrated areas occurs within a distance of about 10 km. This transition coincides with a change in the crustal thickness in the order of 5–10 km, thickening to the south, and in the tectonic regimes. The change in the tectonic regimes towards a stronger extension along the margin of Nicaragua could be the key for understanding the observations: the extension may support the opening of pathways for a wide zone of fluid migration and hydration through the overriding plate which are identified with areas of low Vp, high Vp/Vs and low seismicity
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