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17 q-Hypergeometric and Related FunctionsProperties

§17.8 Special Cases of ψrr Functions

Jacobi’s Triple Product

17.8.1 βˆ‘n=βˆ’βˆžβˆž(βˆ’z)n⁒qn⁒(nβˆ’1)/2=(q,z,q/z;q)∞;

compare (20.5.9).

Analytic Continuation

Note that for the equations below, the constraints are included to guarantee that the infinite series representation (17.4.3) of the ψrr functions converges. These equations can also be used as analytic continuation of these ψrr functions.

Ramanujan’s ψ11 Summation

17.8.2 ψ11⁑(ab;q,z)=(q,b/a,a⁒z,q/(a⁒z);q)∞(b,q/a,z,b/(a⁒z);q)∞,
|b/a|<|z|<1.

Quintuple Product Identity

17.8.3 βˆ‘n=βˆ’βˆžβˆž(βˆ’1)n⁒qn⁒(3⁒nβˆ’1)/2⁒z3⁒n⁒(1+z⁒qn)=(q,βˆ’z,βˆ’q/z;q)∞⁒(q⁒z2,q/z2;q2)∞.

Bailey’s Bilateral Summations

17.8.4 ψ22⁑(b,c;a⁒q/b,a⁒q/c;q,βˆ’a⁒q/(b⁒c)) =(a⁒q/(b⁒c);q)∞⁒(a⁒q2/b2,a⁒q2/c2,q2,a⁒q,q/a;q2)∞(a⁒q/b,a⁒q/c,q/b,q/c,βˆ’a⁒q/(b⁒c);q)∞,
|q⁒a|<|b⁒c|,
17.8.5 ψ33⁑(b,c,dq/b,q/c,q/d;q,qb⁒c⁒d) =(q,q/(b⁒c),q/(b⁒d),q/(c⁒d);q)∞(q/b,q/c,q/d,q/(b⁒c⁒d);q)∞,
|q|<|b⁒c⁒d|,
17.8.6 ψ44⁑(βˆ’q⁒a12,b,c,dβˆ’a12,a⁒q/b,a⁒q/c,a⁒q/d;q,q⁒a32b⁒c⁒d)=(a⁒q,a⁒q/(b⁒c),a⁒q/(b⁒d),a⁒q/(c⁒d),q⁒a12/b,q⁒a12/c,q⁒a12/d,q,q/a;q)∞(a⁒q/b,a⁒q/c,a⁒q/d,q/b,q/c,q/d,q⁒a12,q⁒aβˆ’12,q⁒a32/(b⁒c⁒d);q)∞,
|q⁒a32|<|b⁒c⁒d|,
17.8.7 ψ66⁑(q⁒a12,βˆ’q⁒a12,b,c,d,ea12,βˆ’a12,a⁒q/b,a⁒q/c,a⁒q/d,a⁒q/e;q,q⁒a2b⁒c⁒d⁒e)=(a⁒q,a⁒q/(b⁒c),a⁒q/(b⁒d),a⁒q/(b⁒e),a⁒q/(c⁒d),a⁒q/(c⁒e),a⁒q/(d⁒e),q,q/a;q)∞(a⁒q/b,a⁒q/c,a⁒q/d,a⁒q/e,q/b,q/c,q/d,q/e,q⁒a2/(b⁒c⁒d⁒e);q)∞,
|q⁒a2|<|b⁒c⁒d⁒e|.

Sum Related to (17.6.4)

17.8.8 ψ22⁑(b2,b2/cq,c⁒q;q2,c⁒q2/b2)=12⁒(q2,q⁒b2,q/b2,c⁒q/b2;q2)∞(c⁒q,c⁒q2/b2,q2/b2,c/b2;q2)∞⁒((c⁒q/b;q)∞(b⁒q;q)∞+(βˆ’c⁒q/b;q)∞(βˆ’b⁒q;q)∞),
|c⁒q2|<|b2|.

For similar formulas see Verma and Jain (1983).