2025/11/21 by Jessica Alessandrì, Alessandrì, Jessica, Daniel Loughran +1 · 1 citation
Mathematics · #Algebraic Geometry and Number Theory #Geometry and complex manifolds #Commutative Algebra and Its Applications
paper · pdf · doi:10.48550/arxiv.2511.17456
We consider the Diophantine equation x4 + y4 - w2 = n for n ∈ ℤ, which is related to near misses for the quartic case of Fermat's Last Theorem. For certain n we show that the set of solutions is infinite, or more generally not thin. Our approach is via the geometry of del Pezzo surfaces of degree 2, and we prove a more general result on non-thinness of integral points on double conic bundle surfaces.