97,620 research outputs found
Dealing with Interaction Between Bipolar Multiple Criteria Preferences in PROMETHEE Methods
In this paper, we consider the bipolar approach to Multiple Criteria Decision
Analysis (MCDA). In particular we aggregate positive and negative preferences
by means of the bipolar PROMETHEE method. To elicit preferences we consider
Robust Ordinal Regression (ROR) that has been recently proposed to derive
robust conclusions through the use of the concepts of possible and necessary
preferences. It permits to take into account the whole set of preference
parameters compatible with the preference information provided by the Decision
Maker (DM)
Curvature Quintessence
The issues of quintessence and cosmic acceleration can be discussed in the
framework of higher order theories of gravity. We can define effective pressure
and energy density directly connected to the Ricci scalar of curvature of a
generic fourth order theory and then ask for the conditions to get an
accelerated expansion. Exact accelerated expanding solutions can be achieved
for several fourth order theories so that we get an alternative scheme to the
standard quintessence scalar field, minimally coupled to gravity, usually
adopted. We discuss also conformal transformations in order to see the links of
quintessence between the Jordan and Einstein frames.Comment: 10 pages, LATEX files, to appear on IJMP
- …