1,612 research outputs found
The Contradictions of Constitution-Making in Nigeria
Constitution-making is a popular but poorly understood concept. There are many speculations about the impact of different design processes on constitutional outcomes. Much of the debate reduces to the question of who is involved in the process and for what intent? We consider two central issues in this regard. The first is the problem of institutional self-dealing, or whether governmental organs that have something to gain from the constitutional outcome should be involved in the process. The second deals with the impact of public involvement in the process. Both of these concerns have clear normative implications and both are amenable to straightforward social scientific analysis. This study surveys the relevant research on constitution-making, describes the conceptual issues involved in understanding constitution-making, reviews some claims regarding the process of constitution-making, and presents a set of baseline empirical results from a new set of data on the content and process of constitution-making.Key Words: Constitution, Constituent assembly, Parliament, Sovereign power, General will, Liberty, Adult suffrage, Democracy, Referendum, Enactment, Supremacy, Justiciability, Mandate, Political equality
Angular momentum of free variable mass systems is partially conserved
Variable mass systems are a classic example of open systems in classical mechanics with rockets being a standard practical example. Due to the changing mass, the angular momentum of these systems is not generally conserved. Here, we show that the angular momentum vector of a free variable mass system is fixed in inertial space and, thus, is a partially conserved quantity. It is well known that such conservation rules allow simpler approaches to solving the equations of motion. This is demonstrated by using a graphical technique to obtain an analytic solution for the second Euler angle that characterizes nutation in spinning bodies
Diffuse gamma-ray background and cosmic-ray positrons from annihilating dark matter
We study the annihilating dark matter contribution to the extra-galactic
diffuse gamma-ray background spectrum, motivated by the recent observations of
cosmic-ray positron/electron anomalies. The observed diffuse gamma-ray flux
provides stringent constraint on dark matter models and we present upper bounds
on the annihilation cross section of the dark matter. It is found that for the
case of cored dark matter halo profile, the diffuse gamma-rays give more
stringent bound compared with gamma-rays from the Galactic center. The Fermi
satellite will make the bound stronger.Comment: 20 pages, 11 figures; references added; to appear in PR
Dwarf Dark Matter Halos
We study properties of dark matter halos at high redshifts z=2-10 for a vast
range of masses with the emphasis on dwarf halos with masses 10^7-10^9 Msun/h.
We find that the density profiles of relaxed dwarf halos are well fitted by the
NFW profile and do not have cores. We compute the halo mass function and the
halo spin parameter distribution and find that the former is very well
reproduced by the Sheth & Tormen model while the latter is well fitted by a
lognormal distribution with lambda_0 = 0.042 and sigma_lambda = 0.63. We
estimate the distribution of concentrations for halos in mass range that covers
six orders of magnitude from 10^7 Msun/h to 10^13} Msun/h, and find that the
data are well reproduced by the model of Bullock et al. The extrapolation of
our results to z = 0 predicts that present-day isolated dwarf halos should have
a very large median concentration of ~ 35. We measure the subhalo circular
velocity functions for halos with masses that range from 4.6 x 10^9 Msun/h to
10^13 Msun/h and find that they are similar when normalized to the circular
velocity of the parent halo. Dwarf halos studied in this paper are many orders
of magnitude smaller than well-studied cluster- and Milky Way-sized halos. Yet,
in all respects the dwarfs are just down-scaled versions of the large halos.
They are cuspy and, as expected, more concentrated. They have the same spin
parameter distribution and follow the same mass function that was measured for
large halos.Comment: Accepted to be pusblished by ApJ, 12 pages, 8 figures, LaTeX
(documentclass preprint2). Differences with respect to the previous
submission are: (i) abstract was modified slightly to make it more
transparent to the reader, (ii) an extra figure has been added, and (3) some
minor modifications to the main text were also don
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