3 papers
math.NT2026
Representing rational integers by generalized quadratic forms over quadratic fields
OndÅej Chwiedziuk, MatÄj Doležálek, Emma PÄchouÄková +5
We investigate generalized quadratic forms with values in the set of rational integers over quadratic fields. We characterize the real quadratic fields which admit a positive defin…
math.NT2025
Generalizing Hurwitz's quaternionic proof of Lagrange's and Jacobi's four-square theorems
MatÄj Doležálek
A proof of Lagrange's and Jacobi's four-square theorem due to Hurwitz utilizes orders in a quaternion algebra over the rationals. Seeking a generalization of this technique to orde…
math.NT2024
No proper generalized quadratic forms are universal over quadratic fields
OndÅej Chwiedziuk, MatÄj Doležálek, Simona Hlavinková +5
We consider generalized quadratic forms over real quadratic number fields and prove, under a natural positive-definiteness condition, that a generalized quadratic form can only be…