7,896 research outputs found
Recommended from our members
Pursuing pastoralists: The stigma of shifta during the 'shifta war' in Kenya, 1963-68
This article is available for free download on the publisher’s website.This paper will address the ways in which cultural, economic and political appellations of shifta (bandits or rebels) were used to force social change amongst Somali Kenyans in Kenya's Northern Frontier District (NFD) during the 1963-1968 'Shifta War'. Presenting a work-in-progress the paper reveals how the notion of shifta veiled various forms of violence in the NFD. Consequently, and in common with other investigations of banditry I argue that the Kenyan government 'discovered' a powerful political weapon in shifta that provided a pretext for forcing social and political change. In order to meet the challenges of independence, the shifta 'threat' enabled comprehensive government action against a group of people who were seen to defy the territorial and political constitution of the nation state. This resulted in the misrepresentation of violence in the region and the criminalisation of a community. When looking at state initiatives to contain the 'Shifta War', it is clear that counter-insurgency measures were directed not only at the secessionist fighters but also at the Somali pastoral community more broadly. Forced villagisation, movement restrictions and livestock confiscations criminalised a whole community, and shifta was the justification. In its broader significance this paper challenges the legitimacy of the post-colonial state as an agent of change amongst a group of people who have traditionally existed without regard to state authority
Static, massive fields and vacuum polarization potential in Rindler space
In Rindler space, we determine in terms of special functions the expression
of the static, massive scalar or vector field generated by a point source. We
find also an explicit integral expression of the induced electrostatic
potential resulting from the vacuum polarization due to an electric charge at
rest in the Rindler coordinates. For a weak acceleration, we give then an
approximate expression in the Fermi coordinates associated with the uniformly
accelerated observer.Comment: 11 pages, latex, no figure
Flow Equations for Uplifting Half-Flat to Spin(7) Manifolds
In this short supplement to [1], we discuss the uplift of half-flat six-folds
to Spin(7) eight-folds by fibration of the former over a product of two
intervals. We show that the same can be done in two ways - one, such that the
required Spin(7) eight-fold is a double G_2 seven-fold fibration over an
interval, the G_2 seven-fold itself being the half-flat six-fold fibered over
the other interval, and second, by simply considering the fibration of the
half-flat six-fold over a product of two intervals. The flow equations one gets
are an obvious generalization of the Hitchin's flow equations (to obtain
seven-folds of G_2 holonomy from half-flat six-folds [2]). We explicitly show
the uplift of the Iwasawa using both methods, thereby proposing the form of the
new Spin(7) metrics. We give a plausibility argument ruling out the uplift of
the Iwasawa manifold to a Spin(7) eight fold at the "edge", using the second
method. For eight-folds of the type , being a
seven-fold of SU(3) structure, we motivate the possibility of including
elliptic functions into the "shape deformation" functions of seven-folds of
SU(3) structure of [1] via some connections between elliptic functions, the
Heisenberg group, theta functions, the already known -brane metric [3] and
hyper-K\"{a}hler metrics obtained in twistor spaces by deformations of
Atiyah-Hitchin manifolds by a Legendre transform in [4].Comment: 12 pages, LaTeX; v3: (JMP) journal version which includes clarifying
remarks related to connection between Spin(7)-folds and SU(3)structur
A precise description of the p-adic valuation of the number of alternating sign matrices
Following Sun and Moll, we study v_p(T(N)), the p-adic valuation of the
counting function of the alternating sign matrices. We find an exact analytic
expression for it that exhibits the fluctuating behaviour, by means of Fourier
coefficients. The method is the Mellin-Perron technique, which is familiar in
the analysis of the sum-of-digits function and related quantities
MAGNITUDE ESTIMATION: AN APPLICATION TO FARMERS' RISK-INCOME PREFERENCES
Magnitude estimation, a technique developed by psychology for obtaining ratio scaled values, was used to derive risk-income preferences of ninety-one central Indiana farmers. Both variability-income and bankruptcy-income measures were developed and related to farmers' socio-economic attributes. Wealth and education had limited effects compared with off-farm employment, percent debt and expected levels of income, percent debt and net worth growth. Magnitude estimation provided reliable estimates of preferences. Farmers gave greater importance to the bankruptcy-income measure of risk-income preferences, but only a small portion of the variation of either measure could be explained.Farm Management, Risk and Uncertainty,
Nonexistence of an integral of the 6th degree in momenta for the Zipoy-Voorhees metric
We prove nonexistence of a nontrivial integral that is polynomial in momenta
of degree less than 7 for the Zipoy-Voorhees spacetime with the parameter
Comment: 7 pages, no figure
Coherence properties of the microcavity polariton condensate
A theoretical model is presented which explains the dominant decoherence
process in a microcavity polariton condensate. The mechanism which is invoked
is the effect of self-phase modulation, whereby interactions transform
polariton number fluctuations into random energy variations. The model shows
that the phase coherence decay, g1(t), has a Kubo form, which can be Gaussian
or exponential, depending on whether the number fluctuations are slow or fast.
This fluctuation rate also determines the decay time of the intensity
correlation function, g2(t), so it can be directly determined experimentally.
The model explains recent experimental measurements of a relatively fast
Gaussian decay for g1(t), but also predicts a regime, further above threshold,
where the decay is much slower.Comment: 5 pages, 1 figur
Adiabatic-Impulse approximation for avoided level crossings: from phase transition dynamics to Landau-Zener evolutions and back again
We show that a simple approximation based on concepts underlying the
Kibble-Zurek theory of second order phase transition dynamics can be used to
treat avoided level crossing problems. The approach discussed in this paper
provides an intuitive insight into quantum dynamics of two level systems, and
may serve as a link between the theory of dynamics of classical and quantum
phase transitions. To illustrate these ideas we analyze dynamics of a
paramagnet-ferromagnet quantum phase transition in the Ising model. We also
present exact unpublished solutions of the Landau-Zener like problems.Comment: 12 pages & 6 figures, minor corrections, version accepted in Phys.
Rev.
- …