We give new estimates for the eigenvalues of the hypersurface Dirac operato
r in terms of the intrinsic energy-momentum tensor, the mean curvature and
the scalar curvature. We also discuss their limiting cases as well as the l
imiting cases of the estimates obtained by Zhang and Hijazi [Math. Res. Let
t. 5 (1998) 199; 6 (1999) 465; Ann. Glob. Anal. Geom., in press]. We compar
e these limiting cases with those corresponding to the Friedrich and Hijazi
inequalities. We conclude by comparing these results to intrinsic estimate
s for the Dirac-Schrodinger operator D-f = D - 1/2f. (C) 2001 Elsevier Scie
nce B.V. All rights reserved.