8,194 research outputs found
A new species of Peckia (Diptera: Sarcophagidae) from Costa Rica : with a note on P. pexata (Wulp)
A new species of Peckia Robineau-Desvoidy is described from the coastal dry forest of Guanacaste Province, Costa Rica, viz., Pechia glyphis sp.n., and a key to the ten species of Peckia known from the area is provided. A lectotype is designated for Pechia pexata (Wulp, 1895) and intraspecific variation in male leg setosity and in the morphology of male terminalia are documented
Hertz potentials and asymptotic properties of massless fields
In this paper we analyze Hertz potentials for free massless spin-s fields on
the Minkowski spacetime, with data in weighted Sobolev spaces. We prove
existence and pointwise estimates for the Hertz potentials using a weighted
estimate for the wave equation. This is then applied to give weighted estimates
for the solutions of the spin-s field equations, for arbitrary half-integer s.
In particular, the peeling properties of the free massless spin-s fields are
analyzed for initial data in weighted Sobolev spaces with arbitrary,
non-integer weights.Comment: Regularity assumptions corrected. Orthogonality condition eliminate
Income From Separate Property: Towards a Theoretical Foundation
The characterization of the rents, issues and profits from separate property brought into or acquired during marriage is discussed. There has been no comprehensive treatment of this issue in community property case law and literature in recent years
Spin geometry and conservation laws in the Kerr spacetime
In this paper we will review some facts, both classical and recent,
concerning the geometry and analysis of the Kerr and related black hole
spacetimes. This includes the analysis of test fields on these spacetimes.
Central to our analysis is the existence of a valence Killing spinor,
which we use to construct symmetry operators and conserved currents as well as
a new energy momentum tensor for the Maxwell test fields on a class of
spacetimes containing the Kerr spacetime. We then outline how this new energy
momentum tensor can be used to obtain decay estimated for Maxwell test fields.
An important motivation for this work is the black hole stability problem,
where fields with non-zero spin present interesting new challenges. The main
tool in the analysis is the 2-spinor calculus, and for completeness we
introduce its main features.Comment: 30 pages. To appear in the volume "The Centenary of General
Relativity" in "Surveys in Differential Geometry", edited by Lydia Bieri and
Shing-Tung Yau, in the series "Surveys in Differential Geometry
Simulating the Future Pension Wealth and Retirement Saving in Sweden
In this paper the wealth consequences of the Swedish pension system in the transition from a defined benefit to notional defined contribution system are simulated with almost exact institutional detail, using life cycle profiles estimated from detailed longitudinal micro data. Projected wealth, including different types of pension wealth, are computed and compared between cohorts, gender, wealth deciles and occupational categories. Consistent saving rates and replacement rates allowing consumption to stay constant after retirement are computed. Two different macroeconomic scenarios are considered, one using stylised values for growth, inflation etc. and another using demographically based forecasts. Some conclusions are that the cohorts born in the 1940s are relatively favoured, and so are the wealthiest deciles. Stylised macro assumptions yield more optimistic wealth projections than those corresponding to demographically based projections.Future Pension Wealth; Retirement Saving in Sweden
Maximum observable correlation for a bipartite quantum system
The maximum observable correlation between the two components of a bipartite
quantum system is a property of the joint density operator, and is achieved by
making particular measurements on the respective components. For pure states it
corresponds to making measurements diagonal in a corresponding Schmidt basis.
More generally, it is shown that the maximum correlation may be characterised
in terms of a `correlation basis' for the joint density operator, which defines
the corresponding (nondegenerate) optimal measurements. The maximum coincidence
rate for spin measurements on two-qubit systems is determined to be (1+s)/2,
where s is the spectral norm of the spin correlation matrix, and upper bounds
are obtained for n-valued measurements on general bipartite systems. It is
shown that the maximum coincidence rate is never greater than the computable
cross norm measure of entanglement, and a much tighter upper bound is
conjectured. Connections with optimal state discrimination and entanglement
bounds are briefly discussed.Comment: Revtex, no figure
Sveriges val i ett integrerat Europa
Den hÀr rapporten analyserar Sveriges val mellan en optimal anpassning till EG och medlemskap med hÀnsyn till vÀrdet av svenskt manöverutrymme respektive inflytande pÄ EGs beslut. Vad gÀller handelspolitiken kan Sverige i teorin vara mer öppet utanför EG, men i praktiken förhindras detta av behovet att fÄ tillgÄng till EGs fyra friheter, utan vilka Sverige gÄr miste om investeringar, arbetstillfÀllen och teknologi. Vidare talar behoven av internationellt samarbete vad gÀller miljön, strukturomvandling och ökad konkurrens i Sverige till fördel för medlemskap, medan faran av en svÄrhanterlig EG-byrÄkrati kan tala emot. Avslutningsvis konstateras att EG-debatten behöver analyseras i ett samhÀllsekonomiskt perspektiv, och Àmnen för fortsatt forskning presenteras
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