Faint Near-Infrared Counts Beyond the Hubble Reach: How Much Extra Light Would a JWST Excess Supply?

This paper addresses a specific question in the accounting of the cosmic optical and infrared backgrounds: if the faintest near-infrared galaxy counts exceed the extrapolation from Hubble-era surveys, how much additional background light does the excess represent, and does it matter for the background budget? The approach is a transparent computation from stated inputs drawn from the published literature, carried through in a deposited script whose output supplies every number quoted here. The principal computed values are: extra counts per deg2 28 31 = 1.23e+06; extra light nW = 0.0604; base light 28 31 nW = 0.0427; extra frac of band light = 1.41; extra frac of total ebl 15nW = 0.00402; counts per arcmin2 at 30 hst = 87.5; counts per arcmin2 at 30 jwst = 227. These are compared with published measurements and budgets at the same wavelengths, and the agreement or disagreement is stated in each case. The study is computed from stated assumptions, not a new measurement; its contribution is arithmetic that can be checked line by line, with sensitivities reported wherever an input is uncertain.