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Renormalization for Philosophers by Butterfield and Bouatta in 2014

renormalization, philosophy, physics, papers

1. Introduction

2. Renormalization: the traditional approach

2.1 Prospectus: corrections needed

2.2 Renormalizing a coupling constant

  • 2.2.1 Virtual particles and perturbation theory
  • 2.2.2 Energy scales
  • 2.2.3 Some details

2.3 The cut-off introduced

2.4 Letting the cut-off \[d\] go to zero

2.5 The need for extra terms

  • 2.5.1 The physical rationale
  • 2.5.2 A refined definition of renormalizability

2.6 Which theories are renormalizable?

  • 2.6.1 Dyson’s criterion
  • 2.6.2 Our good fortune

3. The modern approach to renormalization

3.1 Good fortune explained: non-renormalizable terms dwindle at longer distances

  • 3.1.1 Decoupling high-energy behaviour
  • 3.1.2 Spacetime need not be a continuum
  • 3.1.3 Effective theories only?
  • 3.1.4 The renormalization group flow

3.2 Short-distance behaviour: the beta-function and asymptotic freedom

3.3 The perspective from the theory of condensed matter

  • 3.3.1 Continuous phase transitions: scale-invariance
  • 3.3.2 Critical exponents: the correlation length
  • 3.3.3 Short distances: a natural lower limit

4. Nagelian reflections

4.1 Nagel endorsed

4.2 Renormalizability deduced at low energies as a family of Nagelian reductions

4.3 Universality as multiple realizability

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