1
Last Latexed: September 25, 2012 at 10:21
Lecture 8
Free Dirac Particles
Oct. 1, 2012
Last time we learned that we could make a Dirac eld
=
L
R
with the Dirac equation
(i m) = 0
arising from a Lagranian density
L = (i m).
We learned that transforms unde
Physics 615
Homework #2
Fall, 2012
Due: 3 PM, Sept. 21
These problems are all examples of symmetries treated by Noethers theorem.
In evaluating L it is often easier to use the expression
L = x L + i
L
L
L
+ ( i )
+ x ,
i
i
x
in the notation of Lecture 4
Physics 615
Fall, 2012
Homework #1
Due: Sept. 14 at 3:00 P.M.
1 Consider the Lagrangian for two free real scalar elds j with equal
masses, with
2
12
1
L=
2 .
(1)
j j m2
j
2 j =1
2
j =1
Dene without an index to be the complex eld
=
1 + i2
,
2
and rewrite
How to Read a Russian Novel
Quiz format
11.1.16
Our quizzes will occur on the final class session of any given week, and cover all the reading for
that given week. (This means that weeks 3, 4, and 7 will have quizzes on a Tuesday, rather than a
Thursday.)
Current Groups Tied To Presentations: Paper Three
A)
DBS Greater Threat Re: Authenticity
1. Intro/Thesis (Cassie)
2. Turkle quotes (Yisi)
3. Slater quotes (Shawn)
4. Complication/Devils Advocate (Wenjie)
5. Conclusion/Action Horizon (Suyan)
B)
Cyber Great
Remember: Youll be doing things online while not meeting with me during these times/days!
Conferences for LF class on Monday, October 24 @ LSH, B269
10:10-10:20
Qi
10:20-10:30
Cassie
10:30-10:40
Suyang
10:40-10:50
Cecilia
10:50-11:00
Tianning
11:00-11:10
Peer Review Paper Three
Writer: _
Nelson 100: 32/LF/MJ
Reviewer _
Start Time: _ End Time: _
1.
Throughout the paper, distinguish summary, analysis, and quotation by blocking off sections with
brackets and writing S for summary, A for analysis, and Q for q
Dr. Carl Nelson 100: 32/LF/MJ
Paper 4
[Freely adapted from Assignment Question 1 on page 20]
In "The Made-to-Order Savior" Lisa Belkin describes controversial medical technology
that enables parents to conceive a child genetically configured to be a bone-
Computer Exercise Tied To Paper Four
NELSON
1. Read the following passages from Belkin about emotion and empathy:
Hughes is known as a brilliant researcher, simultaneously passionate and wary, a
scientist and physician who chose the field of genetics beca
Physics 615
Fall, 2012
Homework #3
Due Sept. 28 at 3:00 P.M.
1)
In lecture we dened the Pauli-Lubanski vector
1
W = P L ,
2
built of the generators of the Poincar group. Show that
e
(a) [W , P ] = 0,
nd [W , L ], and then show W 2 is a Casimir operator of
Physics 615
Homework #4
Project #1
Fall, 2012
Due: Oct. 5 at 3:00
Due: Oct. 12 at 3:00
Homework #4: [5 pts] Do problem 3.2 from Peskin and Schroeder.
This is a small problem and just a partial homework for this week. The real
work is to get started on the
Last Latexed: September 19, 2012 at 14:42
Lecture 7:
Dirac and Weyl Fields
1
Sept. 27, 2012
Copyright c 2005 by Joel A. Shapiro
We have seen that we expect to construct our eld theory from elds
which transform simply under Poincar transformations, with
e
Last Latexed: September 19, 2012 at 13:56
Lecture 6:
The Poincar Group
e
1
Sept. 24, 2012
Copyright c 2005 by Joel A. Shapiro
Last time we saw that for a scalar eld (x), for every Poincar transfore
mation : x x + c , there is a unitary operator U () which
Last Latexed: September 19, 2012 at 10:43
1
Lecture 5:
Sept. 20, 2012
First Applications of Noethers Theorem
Copyright c 2005 by Joel A. Shapiro
Now it is time to use the very powerful though abstract formalism Noether
developed for continuous symmetries
Last Latexed: September 12, 2012 at 17:47
Lecture 4: Noethers Theorem
1
Sept. 17, 2012
Copyright c 2002, 2005, 2006 by Joel A. Shapiro
I am sure you have heard that for every continuous transformation of the
coordinates that one can make without aecting t
Last Latexed: September 5, 2012 at 11:57
Physics 615, Lectures 1-3
1
Sept. 613, 2012
Introduction
Copyright c 2005 by Joel A. Shapiro
1
Introduction
According to the catalogue, this course is Overview of Quantum Field Theory. Why Overview? When we teach C
1
Physics 615
Wed. Dec. 12, 2012
Homework #12
1
[5 pts] Consider a theory in which the matter elds consist of a single
complex eld, (x), equivalent to two real elds, with gauge transformations
given by a single real scalar eld (x) under which (x) ei(x) (x
Last Latexed: November 7, 2012 at 15:03
Physics 615
Homework #9
1
Fall, 2012
Due: Nov. 19 at 4:00
1
[10 pts] Find the spin-averaged cross section for an electron scattering
o a very heavy Dirac particle of charge e. Do not assume me 0, but
do take the lim
Physics 615
Homework #6.
Fall, 2012
Due Oct. 22 at 3:00
1) Consider adding a cubic interaction to the lagrangian density of Eq. 4.1,
so
1
1
g
L = ( )2 m2 2 3 4 .
2
2
3!
4!
Thus the interaction hamiltonian becomes
Hint =
d3 x
g3
(x) + 4 (x)
3!
4!
which me
Paper 4: Mini-Peer Revision Worksheet (Part I)
NELSON 100:LF/32/MJ
Writer: _
Peer Editor: _
Start Time: _ End Time: _
Write on the students draft or front and back of this sheet.
1.
Read the introductory paragraph (which, for today, should be about a page