For rational α \alpha , the fractional partition functions p α ( n ) p_\alpha (n) are given by the coefficients of the generating function ( q ; q ) ∞ α (q; q)_\infty ^\alpha . When α = − 1 \alpha = -1 , one obtains the usual partition function. Congruences of the form p ( ℓ n + c ) ≡ 0 ( mod ℓ ) p(\ell n + c)\equiv 0 \pmod {\ell } for a prime ℓ \ell and integer c c were studied by Ramanujan. Such congruences exist only for ℓ ∈ { 5 , 7 , 11 } \ell \in \{5, 7, 11\} . Chan and Wang recently studied congruences for the fractional partition functions and gave several infinite families of congruences using identities of the Dedekind eta-function. Following their work, we use the theory of non-ordinary primes to find a general framework that characterizes congruences modulo any integer. This allows us to prove new congruences such as p 57 61 ( 17 2 n − 3 ) ≡ 0 ( mod 17 2 ) p_\frac {57}{61}(17^2 n - 3) \equiv 0 \pmod {17^2} .
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