The most cosmological measurements show that the universe is extremely flat (Ωk≈0) and that the surface brightness of objects scales with the fourth power of redshift (SB∝z^−4). If the universe was still expanding, but had strong negative curvature (Ωk>1), how would SB scale with z? Define α such that SB∝z^α.

* Surface brightness doesn’t scale with redshift if Ωk>1

* α less than −4

* α=−4 (no change)

* α more than −4

á less than −4