  The field-theoretic wavefunction has received renewed attention with the goal
of better understanding observables at the boundary of de Sitter spacetime and
studying the interior of Minkowski or general FLRW spacetime. Understanding the
analytic structure of the wavefunction potentially allows us to establish
bounds on physical observables. In this paper we develop an amplitude
representation for the flat space wavefunction, which allow us to write the
flat space wavefunction as an amplitude-like Feynman integral integrated over
an energy-fixing kernel. With this representation it is possible to separate
the wavefunction into an amplitude part and a subleading part which is less
divergent as the total energy goes to zero. In turn the singularities of the
wavefunction can be classified into two sets: amplitude-type singularities,
which can be mapped to singularities found in amplitudes (including anomalous
thresholds), and wavefunction-type singularities, which are unique to the
wavefunction. As an example we study several tree level and one loop diagrams
for scalars, and explore their singularities in detail.
