883 research outputs found
Polynomial cubic differentials and convex polygons in the projective plane
We construct and study a natural homeomorphism between the moduli space of
polynomial cubic differentials of degree d on the complex plane and the space
of projective equivalence classes of oriented convex polygons with d+3
vertices. This map arises from the construction of a complete hyperbolic affine
sphere with prescribed Pick differential, and can be seen as an analogue of the
Labourie-Loftin parameterization of convex RP^2 structures on a compact surface
by the bundle of holomorphic cubic differentials over Teichmuller space.Comment: 64 pages, 5 figures. v3: Minor revisions according to referee report.
v2: Corrections in section 5 and related new material in appendix
Consumption of Single-Use Plastics by a Commercial Construction Firm: A Case Study
Most construction sites utilize single-use plastic bottles because they are easy to distribute and guarantee fresh, clean drinking water. The number of bottles consumed on a site is usually an unknown quantity and is not a waste center that is commonly focused on. This case study outlines a mid-sized construction company’s rate of consumption of single-use plastic bottles. This study details the specifics of the project including size, type, value, and number of workers onsite. The information was gained through working closely with an onsite contact in a management position. The range of focus has been narrowed to only the amount of labor provided by the general contractor, in order to focus the study to a single company, rather than an entire site. The rate of consumption and number of plastic bottles consumed over the project’s lifetime was studied. The final estimate found that this company’s projects consumed around 530,000 plastic bottles with a team of 72 onsite workers. The final number of plastic bottles consumed will be applied to companies with projects of similar scope, in order to gain more insight into the amount of single-use plastic waste contributed to the environment by the construction industry
Projective structures, grafting, and measured laminations
We show that grafting any fixed hyperbolic surface defines a homeomorphism
from the space of measured laminations to Teichmuller space, complementing a
result of Scannell-Wolf on grafting by a fixed lamination. This result is used
to study the relationship between the complex-analytic and geometric coordinate
systems for the space of complex projective (\CP^1) structures on a surface.
We also study the rays in Teichmuller space associated to the grafting
coordinates, obtaining estimates for extremal and hyperbolic length functions
and their derivatives along these grafting rays.Comment: 31 pages, 4 figure
Becker's conjecture on Mahler functions
In 1994, Becker conjectured that if is a -regular power series,
then there exists a -regular rational function such that
satisfies a Mahler-type functional equation with polynomial coefficients where
the initial coefficient satisfies . In this paper, we prove Becker's
conjecture in the best-possible form; we show that the rational function
can be taken to be a polynomial for some explicit non-negative
integer and such that is -regular.Comment: 19 page
Quantitative Decoding of Interactions in Tunable Nanomagnet Arrays Using First Order Reversal Curves
To develop a full understanding of interactions in nanomagnet arrays is a
persistent challenge, critically impacting their technological acceptance. This
paper reports the experimental, numerical and analytical investigation of
interactions in arrays of Co nanoellipses using the first-order reversal curve
(FORC) technique. A mean-field analysis has revealed the physical mechanisms
giving rise to all of the observed features: a shift of the non-interacting
FORC-ridge at the low-H end off the local coercivity H axis; a stretch
of the FORC-ridge at the high-H end without shifting it off the H axis;
and a formation of a tilted edge connected to the ridge at the low-H end.
Changing from flat to Gaussian coercivity distribution produces a negative
feature, bends the ridge, and broadens the edge. Finally, nearest neighbor
interactions segment the FORC-ridge. These results demonstrate that the FORC
approach provides a comprehensive framework to qualitatively and quantitatively
decode interactions in nanomagnet arrays.Comment: 19 pages, 4 figures. 9 page supplemental material including 3 figure
Business Cycles, Bifurcations and Chaos in a Neo-Classical Model with Investment Dynamics
This paper presents a non-equilibrium dynamic model (NEDyM) that introduces investment dynamics and non-equilibrium effects into a Solow growth model. NEDyM can reproduce several typical economic regimes and, for certain ranges of parameter values, exhibits endogenous business cycles with realistic characteristics. The cycles arise from the investment-profit instability and are constrained by the increase in labor costs and the inertia of production capacity. For other parameter ranges, the model exhibits chaotic behavior. These results show that complex variability in the economic system may be due to deterministic, intrinsic factors, even if the long-term equilibrium is neo-classical in nature
Needed Research on the Englishes of Appalachia
Information about the 79th annual meeting of the Southeastern Conference on Linguistics (SECOL) organized by Jennifer Cramer at the University of Kentucky on April 2012 in Lexington, Kentucky. Topics discussed at the meeting includes current state of research studies on linguistic processes in Appalachia, traditional dialectological and ethnographic. The meeting also featured panel experts including Bridget L. Anderson, Michael Montgomery and Walt Wolfram
The PdBI Arcsecond Whirlpool Survey (PAWS). I. A Cloud-Scale/Multi-Wavelength View of the Interstellar Medium in a Grand-Design Spiral Galaxy
The PdBI (Plateau de Bure Interferometer) Arcsecond Whirlpool Survey (PAWS)
has mapped the molecular gas in the central ~9kpc of M51 in its 12CO(1-0) line
emission at cloud-scale resolution of ~40pc using both IRAM telescopes. We
utilize this dataset to quantitatively characterize the relation of molecular
gas (or CO emission) to other tracers of the interstellar medium (ISM), star
formation and stellar populations of varying ages. Using 2-dimensional maps, a
polar cross-correlation technique and pixel-by-pixel diagrams, we find: (a)
that (as expected) the distribution of the molecular gas can be linked to
different components of the gravitational potential, (b) evidence for a
physical link between CO line emission and radio continuum that seems not to be
caused by massive stars, but rather depend on the gas density, (c) a close
spatial relation between the PAH and molecular gas emission, but no predictive
power of PAH emission for the molecular gas mass,(d) that the I-H color map is
an excellent predictor of the distribution (and to a lesser degree the
brightness) of CO emission, and (e) that the impact of massive (UV-intense)
young star-forming regions on the bulk of the molecular gas in central ~9kpc
can not be significant due to a complex spatial relation between molecular gas
and star-forming regions that ranges from co-spatial to spatially offset to
absent. The last point, in particular, highlights the importance of galactic
environment -- and thus the underlying gravitational potential -- for the
distribution of molecular gas and star formation.Comment: 52 pages, 14 figures, 2 tables, (several minor typos corrected)
accepted by ApJ, high resolution version available, see
http://www.mpia.de/PAWS/pub/paws_schinnerer.pdf ; for more information on
PAWS, further papers and the data, see http://www.mpia.de/PAW
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