14,710 research outputs found
Asymptotic period relations for Jacobian elliptic surfaces
We find an asymptotic description of the period locus of simply connected
Jacobian elliptic surfaces and of the period locus of hyperelliptic curves. The
two descriptions are essentially the same, and are given by the alkanes of
organic chemistry.Comment: The use of the Minimal Model Program has been clarified, as has the
Torelli theorem for special elliptic surface
Siegel modular forms and the gonality of curves
There is no stable Siegel modular form that vanishes on the trigonal locus in
every moduli space of curves.Comment: This version takes into account Yamada's correction of Fay's formula
for the period matrix of a certain degenerating family of curve
"Del Pezzo surfaces as Springer fibres for exceptional groups"
We show that simultaneous log resolutions of simply elliptic singularities
can be constructed inside suitable stacks of principal bundles over elliptic
curves. In particular, we give a direct geometrical construction of del Pezzo
surfaces from the corresponding exceptional simple algebraic groups.Comment: This is a re-written version of "From exceptional groups to del Pezzo
surfaces and simultaneous log resolutions via principal bundles over elliptic
curves". It contains 2 figures. This version corrects one of the figure
Hot Routes: Developing a New Technique for the Spatial Analysis of Crime
The use of hotspot mapping techniques such as KDE to represent the geographical spread of linear events can be problematic. Network-constrained data (for example transport-related crime) require a different approach to visualize concentration. We propose a methodology called Hot Routes, which measures the risk distribution of crime along a linear network by calculating the rate of crimes per section of road. This method has been designed for everyday crime analysts, and requires only a Geographical Information System (GIS), and suitable data to calculate. A demonstration is provided using crime data collected from London bus routes
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