Peyman Milanfar

Peyman Milanfar

@docmilanfar.bsky.social

Distinguished Scientist at Google. Computational Imaging, Machine Learning, and Vision. Posts are personal opinions. May change or disappear over time. http://milanfar.org

3.5K followers262 following230 posts

Most people don't understand that volatility alone can kill your investments start with capital P lose 5% one week: (1-0.05)*P gain 5% the next week: (1+0.05)*(1-0.05)*P. repeat the pattern for 1yr (52 weeks): (1+0.05)^26 *(1-0.05)^26 *P = 0.88P You lost 12% of your money.

It's a cruel irony that those who orchestrated this stock market crash are already insulated from its effects. They will be fine. The real tragedy is that it's the ordinary person – the retiree, the small investor, the hardworking individual – who will suffer the most.

"That Mr. Musk has come to hold so many of the same beliefs about social engineering and economic planning as his grandfather is a testament to his profound lack of political imagination, to the tenacity of technocracy and to the hubris of Silicon Valley." www.nytimes.com/2025/04/04/o...

nytimes.comOpinion | The Rise and Fall of Elon Musk (Gift Article)His belief that liberal democracy has failed and that technologists should lead can be traced to the unusual life of his grandfather.

Every profession has its personality types. In my experience the most difficult people to work with are cynics - no matter how talented they may be. Healthy skepticism is positive and curious. Cynicism is not - it's judgmental. The difference is under-appreciated. 1/2

Warning signs you're dealing with a cynic: * says “that’ll never work...” before any evidence * often assumes the worst of people * every interaction is a 0-sum game * uses criticism to signal competence 2/2

Autoregressive models have become more popular recently. Speaking to people, I get the sense most folks are unaware of the history of the topic in signal processing. In particular, AR across scale got a lot of attention in the 90s. There are a lot of great papers on the subject but one stand out…..

A cipher (or cypher) is an algorithm for performing encryption or decryption - the foundation of all of cryptography research and practice. Not widely appreciated is that the word cipher has its direct origin in the arabic word صفر (sifr) meaning zero. Andصفر itself roots to sanskrit शून्य (śūnya)

A man walks into a library and asks whether they have a book on Pavlov’s dog and Schrodinger’s cat. The librarian thinks for a moment and says “it rings a bell, but I’m not sure if it’s in or not”

I posted this thread four months ago. To my knowledge not a single one of these 10 basic features has been implemented on this website. It can’t be that hard.

Peyman Milanfar@docmilanfar.bsky.social

Here’s why this website is not ready - I’ll start a list: 1. Notifications take for ever to load 2. The mobile - in particular tablet - apps are clunky 3. Since number of views of a post are not shown, it’s impossible to gauge level of engagement with a post 4. Can’t save drafts, let alone threads

In some ways it's harder than ever to land a research job these days - both in academia and in industry. As you prepare for a job talk, consider giving it the following structure - it's hard to give a bad talk that's built like this.: 0/n

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And finally, use the last 5-10 minutes to summarize and talk about what you think are important new directions to pursue in research and how these could have impact for the team and the products of the company, or the department and their areas of interest and growth. 3/n

In some ways it's harder than ever to land a research job these days - both in academia and in industry. As you prepare for a job talk, consider giving it the following structure - it's hard to give a bad talk that's built like this.: 0/n

First, a short snippet of your overall set of technical accomplishments. For instance, you might spend the first 15 minutes giving short overviews of a few of your works/papers - it's also very good to draw a theme across them if there is one. 1/n

Peyman Milanfar reposted

Tweedie's formula is super important in diffusion models & is also one of the cornerstones of empirical Bayes methods. Given how easy it is to derive, it's surprising how recently it was discovered ('50s). It was published a while later when Tweedie wrote Stein about it 1/n

Tweedie's formula is super important in diffusion models & is also one of the cornerstones of empirical Bayes methods. Given how easy it is to derive, it's surprising how recently it was discovered ('50s). It was published a while later when Tweedie wrote Stein about it 1/n

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So to build an MMSE denoiser, all you need is the marginal density P(y) of the noisy measurements; which you can empirically build given just noisy samples. This explains why you don't need clean image to learn to denoise, or to estimate score. 7/n

Tweedie's formula is super important in diffusion models & is also one of the cornerstones of empirical Bayes methods. Given how easy it is to derive, it's surprising how recently it was discovered ('50s). It was published a while later when Tweedie wrote Stein about it 1/n

View full thread

Tweedie's formula is super important in diffusion models & is also one of the cornerstones of empirical Bayes methods. Given how easy it is to derive, it's surprising how recently it was discovered ('50s). It was published a while later when Tweedie wrote Stein about it 1/n

View full thread

Tweedie's formula is super important in diffusion models & is also one of the cornerstones of empirical Bayes methods. Given how easy it is to derive, it's surprising how recently it was discovered ('50s). It was published a while later when Tweedie wrote Stein about it 1/n

Don’t be fooled - SakanaAILabs has very likely already submitted dozens of manuscripts to various conferences to test out its model before productionizing in this sham “experiment”. It’s not an experiment, it’s arbitrage - a core expertise of David Ha from his finance days 1/n

There’s no merit to this work except as a deliberate and troubling strategy: to both create a heavily-cited, machine-generated 'first'; and to effectively normalize such publications. This agenda should be deeply concerning to the AI community. 2/n

The point of this post is not whether the idea is novel or not, but rather that this company has very likely already submitted dozens of manuscripts to various conferences to test out its model before making public this sham “experiment”.

The tech industry in Silicon Valley runs on the considerable talents and work ethic of folks who were not born here. Many of these folks were also trained in this country in our Universities. This is our strength. If we mess with this virtuous cycle, it is at our own peril.

In the 50s a sophisticated theory of how to look for things was developed. Rooted in operations research, it was largely motivated by the loss of an H-bomb and a nuclear submarine in the middle of the ocean Closely related to concepts in reinforcement learning 1/2

It was published a couple of decades after the original (classified) work. Book lays out principles for how to effectively allocate search effort to maximize the probability of finding a target, with limited resources. To my knowledge, it's not known or cited by RL folks 2/2

With today's Turing, it's worth highlighting Barto & Sutton's view of "related work": "In this book, we consider all of the work in optimal control also to be, in a sense, work in reinforcement learning" It's an example of reframing & renaming in CS that's somehow both myopic & maximalist. 1/2

wrecking the economy is going great

Carl Quintanilla@carlquintanilla.bsky.social

In the last two weeks: 1. biggest drop in retail sales in nearly two years 2. biggest drop in personal spending since Feb 2021 3. jobless claims, biggest gain in five months 4. ISM Mfg prices paid, highest since June 2022

Einstein’s eulogy of the great Emmy Noether (1882-1935) “In the judgment of the most competent living mathematicians, Fraulein Noether was the most significant creative mathematical genius thus far produced since the higher education of women began”

meet Chris J Li - this titan of thought has single-handedly conquered the fields of machine learning, optimization, statistics, reinforcement learning, and federated learning. he's not the visionary we want, but judging by the current state of affairs, he may be the one we deserve

When x and y are independent random variables, their joint cumulative dist function (CDF) is the product of the individual CDFs: F(x, y) - F(x)*F(y) = 0 If x,y are only uncorrelated, then Cov(x,y) =0. Can we express uncorrelated-ness in terms of the CDFs as well? Yes. 1/2

This is due to a beautiful and little-known covariance identity by Hoeffding (1940): Cov(x,y) = ∫∫[F(x, y) - F(x)*F(y)] dxdy So the difference between independence and uncorrelated-ness comes down to point-wise equality vs. a (weaker) integral equality between the CDFs. 2/2