5 citations · 8 across the 4 of their papers we have counts for
4 papers
The Picard group of a surface and its reduction modulo
Andreas-Stephan Elsenhans, Jörg Jahnel
We present a method to compute the geometric Picard rank of a surface over . Contrary to a widely held belief, we show it is possible to verify Picard rank using red…
The Diophantine Equation ---a number of improvements
Andreas-Stephan Elsenhans, Jörg Jahnel
The quadruple already known is essentially the only non-trivial solution of the Diophantine equation $x^4 + 2 y^4 = z^4 + 4 w…
The Fibonacci sequence modulo -- An investigation by computer for
Andreas-Stephan Elsenhans, Jörg Jahnel
We show that for primes the period length of the Fibonacci sequence modulo is never equal to its period length modulo . The investigation involves a…
The discriminant of a cubic surface
Andreas-Stephan Elsenhans, Jörg Jahnel
We construct explicit examples of cubic surfaces over such that the 27 lines are acted upon by the index two subgroup of the maximal possible Galois group. This is the simpl…