QFT Student Meetings

last updated: 4.25 PM, Jun 16, 2018

what Students with some prior exposure to QFT meet once a week to systematically discuss advanced concepts of QFT, focusing on renormalization.
when weekly, 12:30, Thursday, L1-047 CCIS
first session: Jan 25, 2018; last session: Apr 26, 2018.
contact Jens Boos (boos@ualberta.ca)
URL http://www.spintwo.net/Courses/QFT-Student-Meetings/

Past meetings

  1. 2018-01-25: organizational issues, brainstorming
  2. 2018-02-01: Why renormalization? Simple examples and general procedure. Based on [1]. [01]
  3. 2018-02-08: Mass and coupling constant renormalization in φ4 theory at 1-loop. Based on Secs. 3.1 and 3.2 in [1]. [01]
  4. 2018-02-15: Running coupling constants, energy scales, and cutoffs. [01, 02]
    2018-02-22: no meeting (reading week)
  5. 2018-03-01: Running coupling constant from the 4-point function in φ4 theory at 1-loop. Clarification of cutoff, energy scale, and reference energy scale. [01]
  6. 2018-03-08: Understanding renormalized coupling constants in terms of the Wilsonian picture; Kadanoff's block-spin [2]. [01]
  7. 2018-03-15: Slow and fast modes, obtaining the beta function in the Wilsonian picture [3,4].
  8. 2018-03-22: From the Ising model to the Landau–Ginzburg functional, based on [5]. [01]
  9. 2018-03-29: Landau–Ginzburg and second-order phase transitions, based on [3,4,5]. [01, 02, 03]
  10. 2018-04-05: Derivation of φ4 β functions at 1-loop in the Wilsonian picture. Comparison to high energy physics results. [01, 02]
  11. 2018-04-12: From β functions to fixed points.
    2018-04-19: no meeting (finals week)
  12. 2018-04-26: Fixed points. Relevant, marginal, and irrelevant couplings. [01, 02]

Suggestions for further meetings

  1. When to do what? Counterterm renormalization vs. wavefunction renormalization vs. other approaches
  2. Calculational techniques: comparing different regularization schemes (Pauli–Villars, dimensional regularization, momentum space cutoff, lattice regularization)
  3. What is power-counting renormalizability? Why is gravity not power-counting renormalizable?

Literature

  1. Markus Luty's Phys851 lecture notes on renormalization, available here.
  2. Wikipedia article on Kadanoff's block-spin.
  3. Ben Simons' Physics Part III lecture notes on the renormalization group, available here (chapter 4)
  4. Subir Sachdev, Quantum Phase Transitions (Cambridge University Press, Cambridge, 1999), Chapter 4.
  5. Alexander Altland and Ben Simons, Condensed Matter Field Theory (Cambridge University Press, Cambridge, 2010), Chapter 5.
  6. additional materials/textbooks: TBD