TY - JOUR ID - Džurina2026 LB - Džurina2026 AU - Džurina, Jozef AU - Baculíková, Blanka TI - Comparison theorems for property (B) of the third-order differential equations with deviating arguments ST - Comparison theorems for property (B) of the third-order differential equations with deviating arguments JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2026 VL - 46 IS - 3 SP - 291 EP - 304 DO - https://doi.org/10.7494/OpMath.202605181 UR - https://doi.org/10.7494/OpMath.202605181 AB - The aim of this paper is to introduce a new comparison theorem (in both delayed and advanced cases) that allows us to investigate the properties of third-order differential equations with quasi-derivatives \[(r_1(t)(r_2(t)y'(t))')'-p(t)y(\tau(t))=0\] using the following simpler differential equations \[(r(t)(r(t)z'(t))')'-p(t)z(\tau(t))=0\] and \[y'''(t)-q(t)y(\sigma(t))=0.\] The obtained comparison principles allow for the immediate transcription of the oscillatory results known for the simpler equations into studied equation with quasi-derivatives. The progress achieved will be illustrated through several examples. KW - canonical equation KW - comparison theorem KW - property (B) SN - 1232-9274 ER -