TY - JOUR
AU - Kontorovich, Alex
AU - Lutsko, Christopher
PY - 2024/03/22
Y2 - 2024/04/18
TI - Effective Counting in Sphere Packings
JF - Journal of the Association for Mathematical Research
JA - J. Assoc. Math. Res.
VL - 2
IS - 1
SE - Articles
DO -
UR - https://jamathr.org/index.php/jamr/article/view/Vol-2Issue-1Paper-2
SP - 15-52
AB - <div class="page" title="Page 3"><div class="layoutArea"><div class="column"><p>Given a Zariski-dense, discrete group, Γ, of isometries acting on (n + 1)- dimensional hyperbolic space, we use spectral methods to obtain a sharp asymptotic formula for the growth rate of certain Γ-orbits. In particular, this allows us to obtain a best-known effective error rate for the Apollonian and (more generally) Kleinian sphere packing counting problems, that is, counting the number of spheres in such with radius bounded by a growing parameter. Our method extends the method of Kontorovich [Kon09], which was itself an extension of the orbit counting method of Lax-Phillips [LP82], in two ways. First, we remove a compactness condition on the discrete subgroups considered via a technical cut- off and smoothing operation. Second, we develop a coordinate system which naturally corresponds to the inversive geometry underlying the sphere counting problem, and give structure theorems on the arising Casimir operator and Haar measure in these coordinates.</p></div></div></div>
ER -