Inflationary dilaton-axion magnetogenesis
  We discuss the generation of primordial magnetic fields during inflation in
the dilaton-axion electromagnetism, in which the dilaton and axion dynamics are
introduced in terms of two time dependent functions of the cosmic scale factor,
$I(a) F^2/4$ and $J(a) F\tilde{F}/4$, respectively, where $F$ is the
electromagnetic field strength and $\tilde{F}$ is its dual. We study the form
of $J(a)$ that can generate a large seed magnetic field in the weak coupling
regime, $I(a)<1$. Although the $J(a)$ function is model dependent, the
axion-photon coupling indeed opens up a new window for a successful
inflationary magnetogenesis.
