I have been long wanting to compare diffusion models to MCMC empirically.
Running Langevin using the annealing scheme from diffusion models results in good samples even for hard targets. Details at jakiw.com/diffusion_as_annea…
1/n
We can quickly create an annealing scheme that replicates that behaviour with the ansatz p_t = p(alpha_t x)^beta_t. This already works much better than the scheme employed before and is implementable.
6/n
However, one can try to approximate such an annealing scheme by choosing p_t = p(alpha * x). A very short first attempt already improves upon the above annealing scheme! 6/n
For a Gaussian mixture, one can calculate the solution to the forward SDE in diffusion models/score-based generative models in closed form. Therefore, we can use this path as smoothed versions and plug it into a Langevin SDE. Turns out, this works nearly perfect! 4/6
Jakiw Pidstrigach retweeted
Great technical explanation and implementation (JAX tutorial included) of diffusion models.
jakiw.com/sgm_intro
The Jupyter notebook here contains an introduction to SGMs using JAX: jakiw.com/sgm_intro
It sets a focus on understanding some theoretical aspects as well as their generalization capabilities.
I created them for the "Accelerating generative models and nonconvex optimisation" workshop at @turinginst. Thanks @odakyildiz for inviting me!
Jakiw Pidstrigach retweeted
That's a wrap! :-) I really enjoyed this week I organised at @turinginst, exploring fundamental aspects of generative models. @TuringChiefSci See turing.ac.uk/research/theory… for details and send me a PM if you are interested!




