Structure formation and the matter power-spectrum in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e427" altimg="si346.svg"><mml:mrow><mml:msub><mml:mrow><mml:mi>R</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">h</mml:mi></mml:mrow></mml:msub><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mi>c</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:math> universe

Inflation drives quantum fluctuations beyond the Hubble horizon, freezing them out before small-scale modes re-enter during radiation dominated epoch, and subsequently decay, while large-scale later matter epoch grow. This distinction shapes power spectrum provides observational evidence in support of standard model. In this paper, we demonstrate that another mechanism, based on fluctuation growth Rh=ct universe, itself an FLRW cosmology with added constraint zero active mass (i.e., ρ+3p=0), also accounts very well for observed spectrum, so feature is not unique to ΛCDM. Rh=ct, shape set by interplay between more rapid decay gravitational potential smaller mode wavelengths longer dynamical timescale larger wavelengths. combination produces a characteristic peak grows both amplitude number as function time. Today, lies at k≈0.02 Mpc−1, agreement Ly-α Planck data. But there no need inflationary expansion, complicated dependence one finds