Testing the Modigliani-Miller theorem directly in the lab

We present an experiment designed to test the Modigliani-Miller theorem. Applying a general equilibrium approach and not allowing for arbitrage among firms with different capital structures, we find that, in accordance with the theorem, participants well recognize changes in the systematic risk of equity associated with increasing leverage and, accordingly, demand higher rate of return. Yet, this adjustment is not perfect: subjects underestimate the systematic risk of low-leveraged equity whereas they overestimate the systematic risk of high-leveraged equity, resulting in a U-shaped cost of capital. A (control) individual decision-making experiment, eliciting several points on individual demand and supply curves for shares, provides some support for the theoreModigliani-Miller theorem, Experiments, Decision making under risk, General equilibrium

Amino-calix[4]arene modified graphite as an electrochemical interface for mercury(II) quantification

A new simple amino-calix[4]arene modified graphitic composite electrode have been prepared and employed in the form of thin film on glassy carbon electrode (GCE) surface as a sensing probe for the measurement of mercury(II) ions. In order to decipher the complexing ability of the modifier towards the metal ions analytical techniques such as cyclic voltammetry and differential pulse anodic stripping voltammetric are used

Semilocal convergence of a continuation method with Hölder continuous second derivative in Banach spaces

AbstractIn this paper, the semilocal convergence of a continuation method combining the Chebyshev method and the convex acceleration of Newton’s method used for solving nonlinear equations in Banach spaces is established by using recurrence relations under the assumption that the second Frëchet derivative satisfies the Hölder continuity condition. This condition is mild and works for problems in which the second Frëchet derivative fails to satisfy Lipschitz continuity condition. A new family of recurrence relations are defined based on two constants which depend on the operator. The existence and uniqueness regions along with a closed form of the error bounds in terms of a real parameter α∈[0,1] for the solution x∗ is given. Two numerical examples are worked out to demonstrate the efficacy of our approach. On comparing the existence and uniqueness regions for the solution obtained by our analysis with those obtained by using majorizing sequences under Hölder continuity condition on F″, it is found that our analysis gives improved results. Further, we have observed that for particular values of the α, our analysis reduces to those for the Chebyshev method (α=0) and the convex acceleration of Newton’s method (α=1) respectively with improved results

A Spallation Model for the Titanium-rich Supernova Remnant Cassiopeia A

Titanium-rich subluminous supernovae are rare and challenge current SN nucleosynthesis models. We present a model in which ejecta from a standard Supernova is impacted by a second explosion of the neutron star (a Quark-nova), resulting in spallation reactions that lead to 56Ni destruction and 44Ti creation under the right conditions. Basic calculations of the spallation products shows that a delay between the two explosions of ~ 5 days reproduces the observed abundance of 44Ti in Cas A and explains its low luminosity as a result of the destruction of 56Ni. Our results could have important implications for lightcurves of subluminous as well as superluminous supernovae.Comment: Accepted/to be published in Physical Review Letters. [ for more info on the Quark Nova, see: http://quarknova.ucalgary.ca/

Quark deconfinement in neutron star cores: The effects of spin-down

We study the role of spin-down in driving quark deconfinement in the high density core of isolated neutron stars. Assuming spin-down to be solely due to magnetic braking, we obtain typical timescales to quark deconfinement for neutron stars that are born with Keplerian frequencies. Employing different equations of state (EOS), we determine the minimum and maximum neutron star masses that will allow for deconfinement via spin-down only. We find that the time to reach deconfinement is strongly dependent on the magnetic field and that this time is least for EOS that support the largest minimum mass at zero spin, unless rotational effects on stellar structure are large. For a fiducial critical density of $5\rho_0$ for the transition to the quark phase ($\rho_0=2.5\times10^{14}$g/cm$^3$ is the saturation density of nuclear matter), we find that neutron stars lighter than $1.5M_{\odot}$ cannot reach a deconfined phase. Depending on the EOS, neutron stars of more than $1.5M_{\odot}$ can enter a quark phase only if they are spinning faster than about 3 milliseconds as observed now, whereas larger spin periods imply that they are either already quark stars or will never become one.Comment: 4 pages, 4 figures, submitted to ApJ

Owls of the forest’s edge

It looked like just a few random vertical poles stuck in between carefully-planted paddy fields adjoining the Kalakad-Mundanthurai Tiger Reserve. The poles were crudely fashioned and topped with flattened pads of hay, stuffed into polythene or white cloth bags

Conservation of a fragmented population of blackbuck (Antilope cervicapra)

The Vallanadu Blackbuck Sanctuary (VBS), Tamil Nadu, India is a small protected area (PA) designated to conserve blackbuck. We did a study on habitat use and suitability in the PA that has come under various management interventions. The occupancy of blackbuck was positively correlated with areas lying within the PA, but the encounter rate of blackbuck was significantly higher in areas outside the PA. Being small in size, VBS may not hold a large population of blackbucks, but may help in saving the species which once widely occurred in the southernmost parts of India