School on Effective Field Theory across Length Scales

Start time: February 22, 2016

Ends on: March 4, 2016

Location: São Paulo, Brazil

Venue: IFT-UNESP

Organizers:

**Ubirajara van Kolck**(IPN Orsay, France & University of Arizona, USA)**Gastão Krein**(IFT-UNESP, Brazil)**Rafael Porto**(IFT-UNESP & ICTP-SAIFR, Brazil)

Lecturers:

**Raphael Flauger**(University of Texas- Austin, USA):*EFT for strings***Hans-Werner Hammer**(Technical University of Darmstadt, Germany):*EFT for cold atoms***David Kaplan***:**EFTs for strong interactions, nuclear physics, and fundamental symmetries***Rafael Porto**(IFT-UNESP & ICTP-SAIFR, Brazil):*EFT for gravitational waves***Leonardo Senatore**(Stanford University, USA):*EFT for cosmology – large scale structures***Ira Rothstein**(Carnegie Mellon University, USA):*General introduction on concepts in EFT*

Description:

Constructing an effective field theory (EFT) to exploit the hierarchy of length scales in a physical system has become an essential skill to be mastered by the modern theoretical physicist. EFTs play a prominent role in almost all branches of modern theoretical physics including particle physics, gravitation, general relativity and condensed matter. This school will provide an overview of the general concepts and principles underlying the construction of an EFT, illustrating these concepts and principles in concrete applications in different areas of physics. The school is intended for PhD students, postdocs and young researchers who are seeking expertise in EFTs. There is no registration fee and limited funds are available for local and travel support of participants.

## Announcement

**List of Confirmed Participants: Updated on Feb 22**

### Satisfaction Survey:

### Photos:

**School Program: PDF version updated on February 29**

Click on the name of the lecturers to watch the videos and on (PDF) or (notes) to download the lecture files.

WEEK 1 |
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Monday, February, 22 |
Tuesday, February 23 |
Wednesday, February 24 |
Thursday, February 25 |
Friday, February 26 |
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9:00 |
9:45 |
Registration |
9:30 |
11:00 |
Lecture 2: Ira Rothstein | Lecture 3: Ira Rothstein | Lecture 4: Ira Rothstein | Lecture 5: Ira Rothstein |

9:45 |
10:00 |
Introduction | 11:00 |
11:30 |
COFFEE BREAK | COFFEE BREAK | COFFEE BREAK | COFFEE BREAK |

10:00 |
11:30 |
Lecture 1: Ira Rothstein (notes) | 11:30 |
13:00 |
Lecture 2: David Kaplan (notes) | Lecture 3: David Kaplan (notes) | Lecture 4: David Kaplan (notes) | Lecture 5: David Kaplan (notes) |

11:30 |
12:00 |
COFFEE BREAK | 13:00 |
15:00 |
LUNCH | LUNCH | LUNCH | LUNCH |

12:00 |
13:30 |
Lecture 1: David Kaplan (notes) | 15:00 |
16:30 |
Lecture 2: Hans-Werner Hammer (PDF) | Lecture 3: Hans-Werner Hammer (PDF) | Lecture 4: Hans-Werner Hammer (PDF) | Lecture 5: Hans-Werner Hammer (video 2) (PDF) |

13:30 |
15:30 |
LUNCH | 16:30 |
17:00 |
COFFEE BREAK | COFFEE BREAK | COFFEE BREAK | COFFEE BREAK |

15:30 |
17:00 |
Lecture 1: Hans-Werner Hammer(PDF) | 17:00 |
19:00 |
Discussion session & Exercises | Discussion session & Exercises | Discussion session & Exercises | Discussion session & Exercises |

17:00 |
17:30 |
COFFEE BREAK | ||||||

17:30 |
18:30 |
Discussion session & Exercises |

**Additional Information:**

**Registration: ALL participants should register**. The registration will be on **February 22** at the institute **from 9:00 to 09:45 am**. You can find arrival instruction at http://www.ictp-saifr.org/?page_id=195

**Accommodation:** Participants whose accommodation has been provided by the institute will stay at The Universe Flat. Each participant, whose accommodation has been provided by the institute, has received the accommodation details individually by email.

**Emergency number:** 9 8233 8671 (from São Paulo city); +55 11 9 8233 8671 (from abroad), 11 9 8233 8671 (from outside São Paulo).

**Ground transportation instructions: **

Ground transportation from Guarulhos Airport to The Universe Flat

Ground transportation from Congonhas Airport to the Universe Flat

Ground transportation from The Universe Flat to the institute

## Lectures Summary:

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**Raphael Flauger** (University of Texas- Austin, USA): *EFT for strings*

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These lectures will be an introduction to effective field theory geared towards an understanding of the effective field theory description of string-like defects in quantum field theories such as cosmic strings or QCD fluxtubes. After a review of the concepts of effective field theory, I will review of the role of symmetries in quantum field theory, both linearly realized and non-linearly realized. I will in particular discuss the consequences of non-linearly realized symmetries for S-matrix elements. I will then review the linear and non-linear sigma model as an illustration before introducing the CCWZ construction and its extension to spacetime symmetries. This will allow us to derive an effective field theory for string-like defects. As an application, I will use this effective field theory, together with the observation that it is integrable at low energies, to compute energy levels of QCD fluxtubes.

=====================================================================================================================================

**Hans-Werner Hammer **(Technical University of Darmstadt, Germany): *EFT for cold atoms*

Ultracold atoms have attained an increasing importance in many fields of physics over the last ten years. In addition to condensed matter physics these fields include statistical physics in nonequilibrium and the physics of strongly interacting quantum systems. The natural connection between ultracold atoms and quantum field theory becomes manifest in few- and many-body systems with resonant interactions. In ultracold atoms, the strength of the interaction can be tuned using Feshbach resonances thus providing a unique test of quantum field theoretical models.

In these lectures, I will focus on the universal low-energy properties of particles with strong interactions. Such systems occur in many areas of physics, including ultracold atoms, adrons, and nuclei. In the unitary limit of infinite scattering length, the two-body interactions do not provide a length scale. Thus the effective field theory describing such a system is scale invariant. In the three-body system, the scale invariance is broken to the subgroup of discrete scale transformations and the Efimov effect occurs. I will explain the general concept of effective field theories and give an overview of their application to ultracold atoms near the unitary limit.

**David Kaplan*** *(University of Washington, USA)*: EFTs for strong interactions, nuclear physics, and fundamental symmetries*

I discuss the connection between singular interactions, renormalization and effective field theory, and discuss how to construct and use effective field theories for a wide range of physical systems including superconductivity, the interactions of pions and nucleons, and physics beyond the Standard Model.

**Ira Rothstein** (Carnegie Mellon University, USA): *General introduction on concepts in EFT*

I will begin by giving a broad introduction to the ideas behind effective field theory,emphasizing the underlying axiomatic reasons for its utility. I will then discuss applications of EFT’s to non-linear classical theories. In particular I will show how EFT can be utilized to attack the problem of black hole binary inspirals, as well as fluctuation induced forces on membranes. I will then introduce the EFT of Fermi surfaces and show how such a theory can be generalized to study systems with van-Hove singularities.

**Leonardo Senatore** (Stanford University, USA): *EFT for cosmology – large scale structures*

During these lectures I will cover some recently developed Effective Field Theories that are useful in Cosmology. First I will introduce the so-called Effective Field Theory of Inflation, which describes Inflation as the theory of the Goldstone Boson of time translations, and I will explain the phenomenology of the resulting Lagrangian. Secondly, I will describe the so-called Effective Field Theory of Cosmological Large Scale Structures. In our current universe, perturbations are small at long distances and large at short distances. An effective field theory for the long fluctuations, which are prone to a perturbative treatment, is obtained after integrating out the non-perturbative short distance physics, in this case the galaxies. I will develop the formalism, explain why this might be useful for next generation experiments, and present the main results so far.

Reference: TASI 2012 lectures on inflation