Plans for the week of April 20-24

Dear all,? welcome back to FYS5429. Today's lecture will be in the form of a recording which will be uploaded later Thursday April 23 or Friday April 24.? Thus there is no lecture today at 1015-12, as announced last week. However, the lab session 12.15-14 will take place as normal with Oda and Ruben being there. Morten is away for a conference.?

The jupyter-notebook for this week is however available (the recording will discuss this notebook), see https://github.com/CompPhysics/AdvancedMachineLearning/blob/main/doc/pub/week13/ipynb/week13.ipynb

After a reminder from last week and Boltzmann machines, see also the codes on Boltzmann machines from last week,? we will discuss Variational Autoencoders. This topic will continue next week as well (and next week and for the rest of the semester all lectures are in person). The plan this week is thus?

Plans for the Week of April 20-24, 2026

Deep generative models: Variational Autoencoders.

Recap?of energy-based models and Boltzmann machines (week 12)

Variational Autoencoders?¡ª full mathematical derivation:

Marginal likelihood and the intractability problem

The ELBO derivation from the KL divergence

Encoder?, decoder?

Reparameterisation trick enabling end-to-end backpropagation

Closed-form KL for Gaussian encoder vs standard Gaussian prior

PyTorch implementation on MNIST

Pros and cons of VAEs

Reading recommendations:

Goodfellow et al, sections 20.10-20.14

Kingma & Welling,?An Introduction to Variational Autoencoders?https://arxiv.org/abs/1906.02691

I apologize for a late email, I forgot to send it out earlier this week.

Best wishes to you all,

Morten, Oda and Ruben