5,851 research outputs found
Promotion and Relegation in Sporting Contests
The conventional model of a team sports league is based on the North American major leagues which have a fixed number of members, entry is rare and only granted by permission of the incumbents (the closed system). European soccer leagues operate a system of promotion and relegation, effectively permitting entry on merit to all-comers (the open system). This paper examines the impact of openness on the incentive of teams to invest (expend effort) and share resources (redistribution) in the context of a Tullock contest. The main conclusion of the paper is that openness tends to enhance effort incentives, but diminishes the incentive to share income.
The Optical Gravitational Lensing Experiment. Variable Stars in Globular Clusters - IV. Fields 104A-E in 47 Tuc
Five fields located close to the center of the globular cluster NGC 104=47
Tuc were surveyed in a search for variable stars. We present V-band light
curves for 42 variables. This sample includes 13 RR Lyr stars -- 12 of them
belong to the Small Magellanic Cloud (SMC) and 1 is a background object from
the galactic halo. Twelve eclipsing binaries were identified -- 9 contact
systems and 3 detached/semi-detached systems. Seven eclipsing binaries are
located in the blue straggler region on the cluster color-magnitude diagram
(CMD) and four binaries can be considered main-sequence systems. One binary is
probably a member of the SMC. Eight contact binaries are likely members of the
cluster and one is most probably a foreground star. We show that for the
surveyed region of 47 Tuc, the relative frequency of contact binaries is very
low as compared with other recently surveyed globular clusters. The sample of
identified variables also includes 15 red variables with periods ranging from
about 2 days to several weeks. A large fraction of these 15 variables probably
belong to the SMC but a few stars are likely to be red giants in 47 Tuc. VI
photometry for about 50 000 stars from the cluster fields was obtained as a by
product of our survey.Comment: Latex file, l-aa style, 10 pages, 7 ps figures included. Submitted to
A&A. Figure 8 available from
ftp://sirius.astrouw.edu.pl/pub/jka/47Tuc/fig8.ps.
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