n the conduction band of a semiconductor, it has a lower valley at the center of the Bril- louin zone, and six upper valleys at the zone boundary along [100]. If the effective mass for the lower valley is 0.1m0 and that for the upper valleys is 1.0m0, find the ratio of the effective density of states in the upper valleys to that in the lower valley.
where m0=9.11E-31kg