In this work we studied the nonlocal spectral problem of second order following :
First we are interested in studying the regularity and almost regularity of boundary
conditions, and we determined in the case q (x) = 0, the conditions for which these boundary
conditions are regular in the spaces L∞ 0,1 and Lp 0,1 , 1 ≤ p <∞.
In addition, we studied the almost regularity of this problem in the case q (x) ≠ 0.
