Mathematicians Map Hidden Structures in Geometric Spaces
Researchers have discovered that certain mathematical objects thought to be scattered are actually connected in ways invisible to previous analysis. The findings could refine how scientists model complex geometric systems, with potential applications in computational geometry and algorithm design where understanding connectivity unlocks efficiency gains.
Originaltitel: Connecting p-gonal loci in the compactification of moduli space
<p>Consider the moduli space M g of Riemann surfaces of genusg≥2 and its Deligne-Munford compactification M g ¯ . We are interested in the branch locus B g for g>2 , i.e., the subset of M g consisting of surfaces with automorphisms. It is well-known that the set of hyperelliptic surfaces (the hyperelliptic locus) is connected in M g but the set of (cyclic) trigonal surfaces is not. By contrast, we show that for g≥5 the set of (cyclic) trigonal surfaces is connected in M g ¯ . To do so we exhibit an explicit nodal surface that lies in the completion of every equisymmetric set of 3-gonal Riemann surfaces. For p>3 the connectivity of the p -gonal loci becomes more involved. We show that for p≥11 prime and genus g=p−1 there are one-dimensional strata of cyclic p -gonal surfaces that are completely isolated in the completion B g ¯ of the branch locus in M g ¯ .</p>