The projective special linear group 
is the group obtained from the special linear group 
on factoring by the scalar matrices contained in that group. It is simple for 
except for
 |  |  | (1) |
 |  |  | (2) |
and is therefore also denoted 
.
Projective Special Linear Group
See also
Projective Special Orthogonal Group, Projective Special Unitary Group, Special Linear GroupExplore with Wolfram|Alpha
References
Conway, J. H.; Curtis, R. T.; Norton, S. P.; Parker, R. A.; and Wilson, R. A. "The Groups
, 
, 
, and 
." §2.1 in Atlas of Finite Groups: Maximal Subgroups and Ordinary Characters for Simple Groups. Oxford, England: Clarendon Press, p. x, 1985.Referenced on Wolfram|Alpha
Projective Special Linear GroupCite this as:
Weisstein, Eric W. "Projective Special Linear Group." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/ProjectiveSpecialLinearGroup.html