181,250 research outputs found
Splittings of groups and intersection numbers
We prove algebraic analogues of the facts that a curve on a surface with
self-intersection number zero is homotopic to a cover of a simple curve, and
that two simple curves on a surface with intersection number zero can be
isotoped to be disjoint.Comment: 40 pages. Published copy, also available at
http://www.maths.warwick.ac.uk/gt/GTVol4/paper6.abs.htm
Testimony of Judith A. Scott Before the Commission on the Future of Worker-Management Relations
Testimony_Scott_011994.pdf: 175 downloads, before Oct. 1, 2020
Multilinguals and Wikipedia Editing
This article analyzes one month of edits to Wikipedia in order to examine the
role of users editing multiple language editions (referred to as multilingual
users). Such multilingual users may serve an important function in diffusing
information across different language editions of the encyclopedia, and prior
work has suggested this could reduce the level of self-focus bias in each
edition. This study finds multilingual users are much more active than their
single-edition (monolingual) counterparts. They are found in all language
editions, but smaller-sized editions with fewer users have a higher percentage
of multilingual users than larger-sized editions. About a quarter of
multilingual users always edit the same articles in multiple languages, while
just over 40% of multilingual users edit different articles in different
languages. When non-English users do edit a second language edition, that
edition is most frequently English. Nonetheless, several regional and
linguistic cross-editing patterns are also present
(Sort of) Testing relativity with extreme mass ratio inspirals
The inspirals of ``small'' () compact bodies through highly
relativistic orbits of massive (several several ) black holes are among the most anticipated sources for the LISA
gravitational-wave antenna. The measurement of these waves is expected to map
the spacetime of the larger body with high precision, allowing us to test in
detail the hypothesis that black hole candidates are described by the Kerr
metric of general relativity. In this article, we will briefly describe how
these sources can be used to perform such a test. These proposed measurements
are often described as ``testing relativity''. This description is at best
somewhat glib: Because -- at least to date -- all work related to these
measurements assumes general relativity as the theoretical framework in which
these tests are performed, the measurements cannot be said to ``test
relativity'' in a fundamental way. More accurately, they test the {\it nature
of massive compact bodies within general relativity}. A surprising result for
such a test could point to deviations from general relativity, and would
provide an experimentally motivated direction in which to pursue tests of
gravity theories beyond GR.Comment: 8 pages, 2 figures, for the Proceedings of the Sixth International
LISA Symposiu
Holding strategies in a bus-route model
A major source of delays in public transportation is the clustering
instability, which causes late buses to become progressively later while the
buses trailing it become progressively earlier. In this paper, we study this
instability and how to neutralize it using the common practices of holding and
schedule slack. Starting with an on-time route, we delay one or more buses at a
single stop, and determine how these delays grow over time. We compare the
effects of two different types of holding on the stability of the system, and
briefly investigate how our results change with the use of timepoints.Comment: 6 pages, 6 figures v2 has been moderately copyedited, but has no new
content Paper has been submitted to Physical Review
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