Boris Bartolomé
We consider the Diophantine equation $X^n-1=B.Z^n$, where $B$ in $\mathbb{Z}$
 is understood as a parameter. We prove that if this equation has a
 solution, then either the Euler totient of the radical, \varphi (rad (B)),
 has a common divisor with the exponent n, or the exponent is a prime and
 the solution stems from a solution to the diagonal case of the
 Nagell–Ljunggren equation: (X^n-1)/(X-1) = n^e.Y^n; e in {0;1}. This
 allows us to apply recent results on this equation to the binary Thue
 equation in question. In particular, we can then display parametrized
 families for which the Thue equation has no solution. The first such
 family was proved by Bennett in his seminal paper on binary Thue
 equations. (This is a joint work with P.Mihailescu).