l/
ODE
Pijk
PCO
PDE
Rijk£
Rjk
Rjk
RF
RG flow
RHS
R, Re, Rm
Rm#
]Rn
SO (n, JR)
Sv.:J for VE 8.:
sect
sn
supp
T (t)
TxM
T;M
tr or trace
v
Voo
v
Vol
w
NOTATION AND SYMBOLS
collection of n-dimensional /'\;-solutions
n-dimensional !1;-solutions with Harnack
v-invariant or unit outward normal
volume of the unit Euclidean (n - 1)-sphere
volume of the unit Euclidean n-ball
ordinary differential equation
the symmetric 3-tensor \liRjk - 'VjRik
positive curvature operator
partial differential equation
xix
2.:m Rijk9me (opposite of Hamilton's convention)
2.:i R~jk = 2.:i,£ giR. RijkR. (components of Ricci)
a symmetric 2-tensor (Rjk = Rjk is a special case)
Ricci flow
renormalization group flow
right-hand side
scalar, Ricci, and Riemann curvature tensors
the quadratic Rm# Rm
n-dimensional Euclidean space
real orthogonal group
set of support functions of .:1 c JRk at V
sectional curvature
unit radius n-dimensional sphere
support of a function
function satisfying ~; = -
tangent space of M at x
cotangent space of M at x
trace
reduced volume
mock reduced volume
vector bundle
volume of a manifold
Perelman's entropy functional
linear entropy functional
Sobolev space of functions with
::; k weak derivatives in LP
space of functions locally in wk,p
tangential component of the vector W
normal component of the vector W
weak maximum principle