|
|
|
s(n) - n > n,
where s() is the divisor
function (PL). The first five abundant numbers are 12, 18, 20, 24, 30
B) = f(A) + f(B), for
any two disjoint (PL) sets A, B on which f is defined..
p(x_0D2xxu(x) + p(x)1Dx
u(u) + p(x)2u(x), the adjoint operator is L(u)
Dxx[p0(x)u(x)] -
Dx[p1(x)U(x)] + p2(x)u(x). (Older
texts use dagger notation to denote an adjoint operator. Relative to a
Hermitian operator, the term "Hermitian conjugate" is sometimes used.


ba
[f(x)]ndx exists, s. t. [f(x)]n = f(x) if |f(x)|
n, = 0 if |f(x)| > n.
, having transition
functions given by 1/z.
< t <
.
k=0 ak (z - z0)k, which
is usually valid only within its radius of convergence. Frequently the
function has a larger domain of definition and can be so extended. (Thus,
extensions of the trigonometric, exponential, logarithmic, power, and
hyperbolic functions from real line R
to entire complex plane, C.)
Similarly, extending values of a function across a branch cut in the
complex plane. Given functions, f1,
f2, defined respectively on domains, W1, W2, with nonepty intersection W1
OP + PO.
Rn is
area-preserving iff m(F(A)) = m(A), for each
subregion Rn,
where m(A) is the n-dimensional measure of A. A
linear transformation is area-preserving iff its
corresponding determinant equals one.
x + iy = x + (
-1)y = |x| eiq, then q is the argument (a.k.a. phase) and
is given by arg(x + iy) = arctan (y/x).
n,
Carl Friedrich Gauss (1777-1855) suggested p
(n) ~ li(x), where li(x) is
the logarithmic integral, defined as the Cauchy principal value (PL) of
li(x)
0xdt/lnt
. Using Soldner's constant, m = 1.4513692346... for which li(x)
= 0, this can be reformulated: li(x)
mxdt/ln t, x >m . Proven independently by J. S. Hadmard
(1865-1963) and Baron de la Vallëe Poussin (1866-1962) proved this theorem by
showing that the Riemann zeta function, PL has no zeros of the
form 1 + (-1)½t, so no deeper values are
required. Other mathematicians improved this proof.
90 = 12. One such
homologue is obtained from the two o-sets: o-{a,
a, b}, o-{a,b,b,c}, with augment, o-{a, a, b} @ o-{a, b, b, c} ~ o-{a, a, a, b, b, b, c}, and
coaugment, coaug, o-{a, a, a, b, b, b, c} @
o-{a, a, b} ~ o-{a, a, b}.