We study the reduced Beurling spectra sp A,V (F ) of functions F ∈ L 1 loc (J, X) relative to certain function spaces A ⊂ L ∞ (J, X) and V ⊂ L 1 (R) and compare them with other spectra including the weak Laplace spectrum. Here J is R + or R and X is a Banach space. If F belongs to the space S ′ ar (J, X) of absolutely regular distributions and has uniformly continuous indefinite integral with 0 ∈ sp A,S(R) (F ) (for example if F is slowly oscillating and A is {0} or C 0 (J, X)),for all ψ ∈ S(R). We show that tauberian theorems for Laplace transforms follow from results about reduced spectra. Our results are more general than previous ones and we demonstrate this through examples 26 August 2011 §1. IntroductionThe goal of this paper 1 is to study the asymptotic behaviour of certain locally integrable functions F : J → X where J denotes R or R + and X is a complex Banach space. Such a study has a long history. It is motivated by Loomis's theorem (see [25] and [24, Theorem 4, p. 92, p. 97]) which gives spectral conditions under which a function F : R → C is almost periodic and by the tauberian theorem of Ingham (see [22] and [2, Theorem 4.9.5, p. 326]) which gives conditions under which lim t→∞ F (t) = 0. Many notions of the spectrum of a function have since been introduced in order to obtain (vector valued) extensions of these results and we will review and compare some of these in this paper. In particular we develop the reduced spectrum sp A (F ) of F relative to various closed subspaces A of BU C(J, X), a spectrum that was introduced before in this context (see [24, Chapter 6.4, p. 91], [6], [7], [2, p. 371], [8] and [17]). Typically the reduced spectrum 1 AMS subject classification 2010: Primary 47A10, 44A10 Secondary 47A35, 43A60.