Complete Solution of the Diophantine EquationX2+1=dY4and a Related Family of Quartic Thue Equations

AbstractIn this paper, we use the method of Thue and Siegel, based on explicit Pade approximations to algebraic functions, to completely solve a family of quartic Thue equations. From this result, we can also solve the diophantine equation in the title. We prove that this equation has at most one solution in positive integers whend⩾3. Moreover, when such a solution exists, it is of the form(u, v)where (u, v) is the fundamental solution ofX2+1=dY2