Lyman-tomography of cosmic infrared background fluctuations with Euclid:
  probing emissions and baryonic acoustic oscillations at z>10
  The Euclid space mission, designed to probe evolution of the Dark Energy,
will map a large area of the sky at three adjacent near-IR filters, Y, J and H.
This coverage will also enable mapping source-subtracted cosmic infrared
background (CIB) fluctuations with unprecedented accuracy on sub-degree angular
scales. Here we propose methodology, using the Lyman-break tomography applied
to the Euclid-based CIB maps, to accurately isolate the history of CIB
emissions as a function of redshift from 10 < z < 20, and to identify the
baryonic acoustic oscillations (BAOs) at those epochs. To identify the BAO
signature, we would assemble individual CIB maps over conservatively large
contiguous areas of >~ 400 sq deg. The method can isolate the CIB spatial
spectrum by z to sub-percent statistical accuracy. We illustrate this with a
specific model of CIB production at high z normalized to reproduce the measured
Spitzer-based CIB fluctuation. We show that even if the latter contain only a
small component from high-z sources, the amplitude of that component can be
accurately isolated with the methodology proposed here and the BAO signatures
at z>~ 10 are recovered well from the CIB fluctuation spatial spectrum. Probing
the BAO at those redshifts will be an important test of the underlying
cosmological paradigm, and would narrow the overall uncertainties on the
evolution of cosmological parameters, including the Dark Energy. Similar
methodology is applicable to the planned WFIRST mission, where we show that a
possible fourth near-IR channel at > 2 micron would be beneficial.
