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02

Loop-space cohomology quotients

Let X=ΩS2X=\Omega S^2 be the based loop space of the 22-sphere, and let R=H(X;Z)R=H^*(X;\mathbb Z) with its usual cup product and cohomological grading. For a 1212-element subset AA of {2,3,,70}\{2,3,\ldots,70\}, define VA=kAR2kV_A=\bigoplus_{k\in A} R^{2k}. For each kAk\in A, let ik:R2kVAi_k:R^{2k}\to V_A be the canonical inclusion into the R2kR^{2k} summand.

Define DAD_A to be the subgroup of VAV_A generated by all elements ik(uv)i_k(u\smile v), where kAk\in A, and uu and vv are homogeneous elements of RR of positive cohomological degree with deg(u)+deg(v)=2k\deg(u)+\deg(v)=2k. In other words, DAD_A is the direct sum, over kAk\in A, of the subgroup of R2kR^{2k} generated by all decomposable cup products in degree 2k2k.

For an abelian group GG and a prime pp, let G[p]G[p^\infty] denote the pp-primary torsion subgroup of GG, meaning the subgroup of elements whose order is a power of pp. The trivial group is considered cyclic. Call AA admissible if, for every prime pp, the group (VA/DA)[p](V_A/D_A)[p^\infty] is cyclic.

Let m=1000003m=1000003, which is prime. Determine the number of admissible 1212-element subsets AA of {2,3,,70}\{2,3,\ldots,70\} such that kAk0(mod37)\sum_{k\in A} k \equiv 0 \pmod{37}, and report the answer modulo mm.