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Supersingular Prime


The term "supersingular prime" has two equivalent characterizations: one group-theoretic and the other number-theoretic.

Group-theoretically, let N be a positive integer and let Gamma_0(N) be the modular group Gamma0. Let X_0(N) be the compactification (by adding cusps) of the orbit quotient Y_0(N)=Gamma_0(N)\H, where H is the upper half-plane. The Fricke involution w_N is induced by the matrix [[0,-1],[N,0]], acting as tau|->-1/(Ntau). For p a prime number, define X_0^+(p)=X_0(p)/<w_p>. Then p is a supersingular prime iff X_0^+(p) has genus 0 (Ogg 1974-1975, p. 7-01).

Equivalently, p is a supersingular prime iff every supersingular elliptic curve over the algebraic closure of the finite field F_p has its j-invariant in F_p (Ogg 1974-1975, p. 7-07).

Supersingular curves were mentioned by Charlie the math genius in the Season 2 episode "In Plain Sight" of the television crime drama NUMB3RS.

There are exactly 15 supersingular primes: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 41, 47, 59, and 71 (OEIS A002267). The supersingular primes are exactly the set of primes that divide the group order of the Monster group.


See also

Modular Group Gamma0, Monster Group

This entry contributed by John McKay

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References

Conway, J. H.; Curtis, R. T.; Norton, S. P.; Parker, R. A.; and Wilson, R. A. Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups. Oxford, England: Clarendon Press, 1985.Conway, J. H. and Norton, S. P. "Monstrous Moonshine." Bull. London Math. Soc. 11, 308-339, 1979. https://doi.org/10.1112/blms/11.3.308.Ogg, A. P. "Automorphismes de courbes modulaires." Séminaire Delange-Pisot-Poitou. Théorie des nombres 16, 7-01-7-08, 1974-1975. https://www.numdam.org/article/SDPP_1974-1975__16_1_A4_0.pdf.Ogg, A. P. "Modular Functions." In The Santa Cruz Conference on Finite Groups. Held at the University of California, Santa Cruz, Calif., June 25-July 20, 1979 (Ed. B. Cooperstein and G. Mason). Providence, RI: Amer. Math. Soc., pp. 521-532, 1980.Silverman, J. H. The Arithmetic of Elliptic Curves. New York: Springer-Verlag, 1986.Silverman, J. H. Advanced Topics in the Arithmetic of Elliptic Curves. New York: Springer-Verlag, 1994.Sloane, N. J. A. Sequence A002267 in "The On-Line Encyclopedia of Integer Sequences."

Referenced on Wolfram|Alpha

Supersingular Prime

Cite this as:

Weisstein, Eric W., with contributions by John McKay. "Supersingular Prime." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/SupersingularPrime.html

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