  The central puzzle of the cuprate superconductors at low hole density is the
nature of the pseudogap regime. It has a number of seemingly distinct
experimental signatures: a suppression of the paramagnetic spin susceptibility
at high temperatures, low energy electronic excitations that extend over arcs
in the Brillouin zone, X-ray detection of charge density wave order at
intermediate temperatures, and quantum oscillations at high magnetic fields and
low temperatures. We show that a model of competing charge density wave and
superconducting orders provides a unified description of the intermediate and
low temperature regimes. We treat quantum oscillations at high field beyond
semiclassical approximations, and find clear and robust signatures of an
electron pocket compatible with existing observations; we also predict
oscillations due to additional hole pockets. In the zero field and intermediate
temperature regime, we compute the electronic spectrum in the presence of
thermally fluctuating charge density and superconducting orders. Our results
are compatible with experimental trends.
