Type: Article
Publication Date: 1994-09-01
Citations: 84
DOI: https://doi.org/10.1515/crll.1994.454.59
In 1994, Brüdern and Fouvry [1] initiated the investigation of Lagrange's four squares theorem with almost prime variables.In this paper, we prove that every sufficiently large integer, congruent to 4 modulo 24, can be represented as a sum of four squares of integers, each of which has at most four prime factors.Instead of the four-dimensional vector sieve developed by Brüdern and Fouvry [1], we establish this result by combining the threedimensional sieve and the switching principle.