  We develop a very general perturbative theory of time-dependent transport in
a weak tunneling junction which is independent of experimental details and on
many-body correlated states in the coupled conductors. These can be similar or
different, with arbitrary internal or mutual interactions, superconducting
correlations, disorder, and coupled to an electromagnetic environment or other
quantum systems. The junction can be spatially extended, and is subject,
simultaneously, to time-dependent voltage, local magnetic field and modulation
of the tunneling amplitudes. All observables at arbitrary frequencies: average
current, non-equilibrium admittance and current correlations can be expressed
in a universal way through the out-of-equilibrium DC current only, yielding
perturbative time-dependent non-equilibrium fluctuation relations. In
particular, charge fluctuations are shown to be universally super-poissonian,
and to become poissonian if the junction is driven by a series of Lorentzian
pulses. We also generalize, for constant voltage and tunneling, the poissonian
shot noise and the fluctuation relation between the derivatives of the noise
and the conductance. Thus we provide a compact, general and transparent
unifying theory at arbitrary dimension, in contrast with involved derivations
based explicitly on particular models and profiles of a single time-varying
field.
