5 research outputs found
Generalized and Higher Dimensional Apollonian Packings
In this thesis, we show that circle, sphere, and higher dimensional sphere packings may
be realized as subsets of the boundary of hyperbolic space, subject to certain symmetry
conditions based on a discrete group of motions of the hyperbolic space. This leads to
developing and applying counting methods which admit rigorous upper and lower bounds on
the Hausdorff (or Besikovitch) dimension of the residual set of several generalized Apollonian
circle packings. We find that this dimension (which also coincides with the critical exponent
of a zeta-type function) of each packing is strictly greater than that of the Apollonian
packing, supporting the unsolved conjecture that, among the many possible disk tilings of
the plane, the Apollonian packing has the smallest possible residual set dimension. The
obtained rigorous bounds are also consistent with the heuristic estimates calculated herein
A Note on Fourier Eigenfunctions in Four Dimensions
In this note, we exhibit a weakly holomorphic modular form for use in
constructing a Fourier eigenfunction in four dimensions. Such auxiliary
functions may be of use to the D4 checkerboard lattice and the four dimensional
sphere packing problem.Comment: 5 pages, comments welcom
Charter Schools as Nation Builders: Democracy Prep and Civic Education
This policy brief is the first in a series of in-depth case studies exploring how top-performing charter schools have incorporated civic learning in their school curriculum and school culture. For more information about AEI's Program on American Citizenship