B8284 - GRAVITATIONAL WAVE PHYSICS

Learning outcomes

At the end of the course, the students will have a comprehensive understanding of the experimental and phenomenological aspects ofGravitationalWave Physics. They will acquire knowledge about the design and operation of experimental detectors. Specifically, the student will develop proficiency in analyzinggravitationalwave data, mastering both classical detection techniques and emerging approaches based on innovative solutions, including machine learning.

Course contents

Introduction to Gravitational Waves (6 hours)

• Einstein’s equations in the weak-field regime and the resulting wave equation;

• The metric of a gravitational wave in the transverse-traceless (TT) gauge;

• Expression of the far-field in terms of the quadrupole moment;

• The effect of gravitational waves on matter and comparison with electromagnetic waves;

• Indirect evidence of their existence through the Hulse-Taylor binary system.

Astrophysical Sources of Gravitational Waves (12 hours)

• Compact binary systems composed of black holes and neutron stars;

• Supernovae and gravitational core collapse of stars;

• The cosmological background of primordial gravitational waves;

• Continuous waves emitted by rotating asymmetric neutron stars;

• Exotic sources.

Generation of Gravitational Waveforms (6 hours)

• Numerical relativity simulations of compact object mergers;

• Post-Newtonian approximations in the weak-field regime;

• Perturbation theory and description of black hole ringdowns;

Detection of Gravitational Waves (12 hours)

• Fundamental principles of interferometric detection;

• Description of ground-based detectors such as LIGO, Virgo, and KAGRA;

• Overview of future projects such as the Einstein Telescope;

• Main sources of noise and technical challenges in detection;

• Calibration, sensitivity curves, and instrumental limits.

Stochastic Process Analysis and Data Analysis Strategies (16 hours)

• Study and analysis of noise-dominated time series;

• Advanced signal analysis techniques;

• Bayesian inference and probabilistic approaches;

• Applications of machine learning for signal identification and classification;

• Laboratory sessions on signal data analysis and noise characterization.

Astrophysical Results and Scientific Implications (8 hours)

• Observations of binary black hole mergers;

• Neutron star merger events;

• The role of multi-messenger astronomy in the gravitational wave context;

• Contributions to the study of the equation of state of dense nuclear matter;

• Experimental tests of general relativity in the strong-field regime;

• Cosmological applications, such as independent measurements of the Hubble constant.

Readings/Bibliography

Misner, Thorne, Wheeler, Gravitation, W.H. Freeman & Co, 1973.

Fundamentals of Interferometric Gravitational Wave Detectors, Peter R Saulson (Syracuse University, USA)April 2017

Teaching methods

The course is conducted through in-person lectures. In addition to the theoretical content, practical exercises are included to prepare for the final exam, as well as programming tasks and real data analysis.
Attendance is highly recommended as it facilitates the learning of concepts and knowledge, although it does not directly affect the final grade.

Assessment methods

The final exam consists of a seminar on an assigned data analysis task.

Teaching tools

The repository at virtuale.unibo.it contains the exercises proposed during lectures. 

Students with specific learning disorders (SLD) or temporary/permanent disabilities:

We recommend contacting the University Office responsible for support services in a timely manner (https://site.unibo.it/studenti-con-disabilita-e-dsa/it) [https://site.unibo.it/studenti-con-disabilita-e-dsa/it):] ). The office will evaluate the students' needs and, where appropriate, propose possible accommodations. These must in any case be submitted for approval at least 15 days in advance to the course instructor, who will assess their suitability also in relation to the learning objectives of the course.

Office hours

See the website of Elena Cuoco