A hyperelliptic diophantine equation related to imaginary quadratic number fields with class number 2.
Let a, b, c be relatively prime positive integers such that . Jeśmanowicz conjectured in 1956 that for any given positive integer n the only solution of in positive integers is x=y=z=2. If n=1, then, equivalently, the equation , for integers u>v>0, has only the solution x=y=z=2. We prove that this is the case when one of u, v has no prime factor of the form 4l+1 and certain congruence and inequality conditions on u, v are satisfied.
We show that the system of equations , where is a triangular number, has infinitely many solutions in integers. Moreover, we show that this system has a rational three-parameter solution. Using this result we show that the system has infinitely many rational two-parameter solutions.
Let a,b,c be fixed coprime positive integers with mina,b,c > 1, and let m = maxa,b,c. Using the Gel’fond-Baker method, we prove that all positive integer solutions (x,y,z) of the equation satisfy maxx,y,z < 155000(log m)³. Moreover, using that result, we prove that if a,b,c satisfy certain divisibility conditions and m is large enough, then the equation has at most one solution (x,y,z) with minx,y,z > 1.