Lectures in Differential Geometry and General Relativity




This is a set of on-line lectures dealing with classical General Relativity and Differential Geometry. As of now the lectures are classified into topics. If you are interested in a topic which is not listed, please contact me at alfonso AT math.uminho.pt and I will check if I can add a lecture about the corresponding topic. Of course, I accept questions about the lectures posted here.



Lectures posted so far:




Penrose diagrams and global properties of the space-time

In these lectures I introduce the notion of conformal boundary and conformal compactification. I explain in detail the conformal compactification of Minkowski, de Sitter and anti de Sitter solutions. I also introduce the notion of Penrose diagram and construct the Penrose diagram for a number of exact solutions of the Einstein field equations. To follow the lectures of this topic you are assumed to be familiar with the representation of the space-time as a Lorentzian manifold. You also need to know that observers in the space-time are represented by (inextendible) causal curves.

Brief introduction of the notion of conformal boundary

Conformal compactification of the Minkoski solution

Lecture contents:

Conformal compactification of de Sitter and anti-de Sitter.

Lecture contents:
  • Maximally symmetric spaces in pseudo-Riemannian geometry.
  • Maximally symmetric solutions of the Einstein equations: Minkowski, de Sitter and anti-de Sitter solutions.
  • Embedding of de Sitter solution in five dimensional flat space-time.
  • The conformal embedding of de Sitter solution into the Einstein static universe. Construction of the conformal boundary and study of the global properties of the de Sitter solution.
  • Embedding of anti de Sitter solution in five dimensional flat space-time.
  • The conformal embedding of anti-de Sitter solution into the Einstein static universe. Construction of the conformal boundary and study of the global properties of the anti-de Sitter solution.

Penrose diagram of the Schwarzschild solution.

Lecture contents:
  • Spherically symmetric space-times in dimension four.
  • The notion of Penrose diagram of a spherically symmetric space-time.
  • Example: Penrose diagram of the Minkowski space-time.
  • The Schwarzschild solution in Schwarzschild coordinates.
  • Penrose diagram of the Schwarzschild solution and construction of the Kruskal extension.
  • Global causal properties of the Schwarzschild solution.

Penrose diagram of the Reissner Nordström solution.

Lecture contents:
  • The Reissner-Nordström solution and its classification: m>q, m=q and m< q.
  • Penrose diagram of the case m>q: maximal extension and global causal properties.
  • Penrose diagram of the case m=q: maximal extension and global causal properties.
  • Penrose diagram of the case m< q: maximal extension and global causal properties.


Relativistic Cosmology

In this lecture I explain in detail the ΛCDM model and its implications to the global causal structure of the universe. I also compute the Penrose diagram of the universe using the material introduced in the lectures about Penrose diagrams. The lecture can be understood as a mini-course in Cosmology. Familiarity with elementary General Relativity is assumed.

Lecture contents:
  • The cosmological principle and the Weyl postulate. Scales of the known Universe.
  • Construction of the FLRW space-time and its classification: open, flat and closed universes.
  • The cosmological redshift and blueshift. Relation to the expansion and contraction of the universe.
  • Matter-energy content of the universe. Review of geometrized units.
  • The FLRW cosmological models and their dynamics. Cosmological equations.
  • Cold dark matter hypothesis and its implications for the dynamics of the universe. Definitions of ΩΛ, ΩM, ΩR and Ωk.
  • The ΛCDM model.
  • Construction of the Penrose diagram of the Universe and discussion of its global properties.


Other lectures





A brief course on probability & statistics

Brief course taught at the undergraduate level. The course material can be downloaded here (in Spanish).

Course contents:
  • Introduction to probability. Sample space and definition of a probability space.
  • Conditional probability. Bayes theorem.
  • Random variable and probability distributions. Continuous and discrete probability distributions.
  • The binomial distribution.
  • The Poisson distribution.
  • The hypergeometric distribution.
  • The normal distribution
  • The central limit theorem.
  • Notion of sample statistic.
  • Estimators.
  • Confidence intervals.

A course about the xAct system for tensor analysis

Course being taught at the graduate level. The course slides can be found here.

Course contents:
  • Package xTensor: coordinate-free tensor analysis.
  • Package xCoba: tensor analysis in coordinates.
  • Package xTerior: exterior calculus and its applications.
  • Package Spinors: Penrose's spinor analysis in General Relativity.

On-line presentation about xTerior: