Part 9, 10, 11
Outline, Schedule

PHYS 424 Notes

Part 10

  1. Chapter 3
    1. Linear Algebra
      1. Vectors

Concept Abstract notation Ordinary vectors        Matrices        Wave Functions
[square well 0 to a]
Vector |a>, |b>, ... r (a)
(b)
(c)
y(x)
Scalar a, b, ...
In general, the complex numbers
Addition |a> + |b> = |g> r1 + r2 = r3 (a)    (d)    (a+d)
(b) + (e) = (b+e)
(c)    (f)    (c+f)
y1(x) +y2(x) = y3(x)
Zero vector |a> + |0> = |a>
|a> + | -a> = |0>
0 (0)
(0)
(0)
0
Scalar multiplication a |a> = |g>
Linear combination of vectors a |a> + b |b> + c |g> + ...
Linear independence a |a> + b |b> + c |g> + ... = |0> implies a = b = c = ...=0
Basis A set |e1> , |e2> , ... of linearly-independent vectors that span the space 1x, 1y, 1z (1)    (0)     (0)
(0) ,  (1)  ,  (0)
(0)    (0)     (1)
sin (npx/a)
Components if |a> = Sn an |an> , the set of coefficients (a1 , a2 , ...) rx , ry , rz Obvious If y(x) = Sn ansin(npx/a), the set (a1 , a2 , ...,)

      1. Inner products

Concept Abstract notation Ordinary vectors        Matrices        Wave Functions
[square well 0 to a]
Inner product <a | b> = <b | a>*

<a | a> ³ 0 and <a | a> = 0 <=> | a> = | 0>

<a|  [b | b > + c | g>]
= b <a | b > + c <a | g >

r1 . r2 Sn an* bn ò dx y1*(x) y2(x)
Norm ||a|| = Ö <a | a> Ör2 Ö Sn |an|2 Ö ò dx |y(x)|2
Orthonormal set <en | em> = dnm See bases above
Complete set Sn | en >< en | = 1
Last Revised 01/09/26

Part 9, 10 11
Outline, Schedule