The aim of this talk is to explain a strategy that allows us to bound
the Fourier coefficients
of a large class of not necessarily bounded multiplicative functions.
The interest in this result
lies in the fact that the strategy can be adapted to show that these multiplicative
functions give
rise to functions that are orthogonal to linear nilsequences when applying a
‘W-trick’. This, in
turn, provides one of two necessary steps for an application of the Green-Tao methods,
which
can be employed to asymptotically evaluate linear correlations
of these multiplicative functions.