The goal of this paper is an exhaustive investigation of the link between the tail measure of a regularly varying time series and its spectral tail process, independently introduced in Owada and Samorodnitsky (2012) and Basrak and Segers (2009). Our main result is to prove in an abstract framework that there is a one to one correspondance between these two objets, and given one of them to show that it is always possible to build a time series of which it will be the tail measure or the spectral tail process. For non negative time series, we recover results explicitly or implicitly known in the theory of maxstable processes.
Tail measures on a metric space.2.1. Framework. The mathematical setting is the following. Let pE, Eq be a measurable cone, that is a measurable space together with a multiplication by positive scalars pu, xq P p0, 8qˆE Þ Ñ ux P E , which is measurable with respect to the product σ-field Bp0, 8q b E{E and satisfies 1x " x , upvpxqq " puvqx , u, v ą 0 , x P E .We assume that the cone admits a zero element 0 E P E such that u0 E " 0 E for all u ą 0 and that it is endowed with a pseudonorm, i.e. a measurable function }¨} E : E Þ Ñ r0, 8q such that }ux} E " u}x} E for all u ą 0, x P E and }x} E " 0 implies x " 0 E . The triangle inequality is not required.The space E Z of E-valued sequences is endowed with the cylinder σ-algebra F " E bZ and a generic sequence is denoted x " px h q hPZ . The sequence identically equal to 0 E is denoted by imsart-aap ver.