*(Homotopy Type Theory)*

The Department of Mathematics at Johns Hopkins University solicits applications for one two-year postdoctoral fellowship beginning Summer 2021 (with some flexibility in the start and end dates). Th…

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# Category: Mathematics

Read Postdoctoral position in HoTT at Johns Hopkins University by Emily Riehl *(Homotopy Type Theory)*
Bookmarked The ergodicity problem in economics by *(Nature Physics volume 15, pages1216–1221(2019))*
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Read Shape by Jordan Ellenberg: 9781984879059 *(PenguinRandomhouse.com)*
Read - Want to Read: Shape: The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else by *(Penguin Press)*
Bookmarked Ergodicity: Definition, Examples, And Implications, As Simple As Possible *(Gumroad)*
Liked a tweet *(Twitter)*
Read Tombstone (typography) *(Wikipedia)*
Read How a brand of chalk achieved cult status among mathematicians *(CNN)*
Bookmarked Meet a Mathematician! *(sites.google.com)*
Bookmarked SMB 2020 Annual Meeting (Schedule) *(SMB 2020)*
Liked a tweet *(Twitter)*
Bookmarked Mathcha - Online Math Editor *(mathcha.io)*
Bookmarked Lecture Notes by Arun Debray *(web.ma.utexas.edu)*

The Department of Mathematics at Johns Hopkins University solicits applications for one two-year postdoctoral fellowship beginning Summer 2021 (with some flexibility in the start and end dates). Th…

The ergodic hypothesis is a key analytical device of equilibrium statistical mechanics. It underlies the assumption that the time average and the expectation value of an observable are the same. Where it is valid, dynamical descriptions can often be replaced with much simpler probabilistic ones — time is essentially eliminated from the models. The conditions for validity are restrictive, even more so for non-equilibrium systems. Economics typically deals with systems far from equilibrium — specifically with models of growth. It may therefore come as a surprise to learn that the prevailing formulations of economic theory — expected utility theory and its descendants — make an indiscriminate assumption of ergodicity. This is largely because foundational concepts to do with risk and randomness originated in seventeenth-century economics, predating by some 200 years the concept of ergodicity, which arose in nineteenth-century physics. In this Perspective, I argue that by carefully addressing the question of ergodicity, many puzzles besetting the current economic formalism are resolved in a natural and empirically testable way.

It’s supremely sad that a paper in Nature should “math shame” ergodic theory this way. What the hell is going on?

From the New York Times-bestselling author of How Not to Be Wrong, himself a world-class geometer, a far-ranging exploration of the power of geometry, which turns out to help us think better about practically...

From the New York Times-bestselling author of How Not to Be Wrong, himself a world-class geometer, a far-ranging exploration of the power of geometry, which turns out to help us think better about practically everything

How should a democracy choose its representatives? How can you stop a pandemic from sweeping the world? How do computers learn to play chess, and why is learning chess so much easier for them than learning to read a sentence? Can ancient Greek proportions predict the stock market? (Sorry, no.) What should your kids learn in school if they really want to learn to think? All these are questions about geometry.

For real. If you're like most people, geometry is a sterile and dimly-remembered exercise you gladly left behind in the dust of 9th grade, along with your braces and active romantic interest in pop singers. If you recall any of it, it's plodding through a series of miniscule steps, only to prove some fact about triangles that was obvious to you in the first place. That's not geometry. OK, it is geometry, but only a tiny part, a border section that has as much to do with geometry in all its flush modern richness as conjugating a verb has to do with a great novel.

Shape reveals the geometry underneath some of the most important scientific, political, and philosophical problems we face. Geometry asks: where are things? Which things are near each other? How can you get from one thing to another thing? Those are important questions. The word geometry, from the Greek, has the rather grand meaning of measuring the world. If anything, that's an undersell. Geometry doesn't just measure the world - it explains it. Shape shows us how.

Some reviews of Luca's previous books"This book is like a magnificent suspension bridge, linking the science of the human brain to the practical craft of applying it in everyday life. I loved it." – Rory Sutherland, Ogilvy's Vice Chairman“A SUPERB book […] by one of the profound thinkers in our field [behavioral economics].” – Michal G. BartlettWhat's ergodicity, and why it matters?"The Most Important Property to Understand in Probability, in Life, in Anything." – Nassim Nicholas Taleb on ergodicity."I think the most under-rated idea is ergodicity." – David Perell, author.Is ergodicity the most important concept in decision-making and behavioral sciences? (Yes.)Is it relevant for you in your daily life? (Yes.)Is it possible to explain it so simply that a grandma or a high-schooler can understand it? (Yes.)Even if they know nothing about maths? (Yes.)That's because ergodicity is an important idea with so many practical applications. Sadly, most books describe it in a very technical way, making it inaccessible to most people.In this short book, 6-times author Luca Dellanna describes ergodicity as simply as possible. You will read stories about how not knowing about it destroyed his cousin’s career as a skier, or how misunderstanding it caused additional deaths during the pandemic. You will learn how to spot situations in which ergodicity matters and the three strategies to react appropriately.The book is approximately 166 pages long, of which 143 are pure content and the rest tables of content, etc.This page sells the eBook / Kindle version. Around mid-November, the paperback version will become available on Amazon and in selected stores (e.g., most Barnes & Noble).Who is this book for?This book is for readers interested in growing themselves, their career, or their business, and who want to learn about ergodicity and its practical applications without having to understand its mathematical foundation. No mathematical knowledge is required, only a high-school level understanding of English.Readers who want to master the theory and mathematical foundation of ergodicity are better off reading a more formal manuscript. This book is not a substitute for it, but a complement.You might also be interested in my second Roam book, on management (link).About the authorLuca Dellanna is the author of 7 books. He is a researcher in complexity science and emergent behaviors, and an operational excellence consultant. He spoke at Nudgestock and regularly teaches management workshops and risk management courses.His personal website is Luca-Dellanna.com and his Twitter is @DellAnnaLuca.What you will getBy purchasing this book, you will receive all of the following:PDF version.ePub version (compatible with Apple Books & other eBook readers).mobi version (Kindle)Moreover, you will get added to my mailing list, where I frequently publish essays that do not make it into books.The Roam versionThis book is also available as a Roam Research graph.Roam is a website that shows content in an interconnected way, a bit like Wikipedia. Reading the book this way will allow you to go back and forth content at your pace and following your interests."Ten minutes in, and I'm already questioning whether I'll want to read another non-fiction book *not* published in Roam format. How fascinating and so very valuable. Thank you Luca Dellanna" – Conor M. Ogle (link)Important: reading the Roam version requires a pre-existing Roam subscription, which is not included in this bundle.If you purchase the Roam version, you will receive the eBook in 3 formats (PDF, Kindle, and ePub) and the Roam version (as an editable .json export of the book) and a document suggesting how to import the Roam book and use it and the option to email me to request access to a live, read-only version of the book.Patron's supportThank you very much for your support, it helps me spending more time on my research.I will also add your name as a Patron in the acknowledgment section of the future editions of the book.Some more reviews of Luca's books“Luca’s book was so helpful to my work. Opened my eyes up to some more reasons why change is so hard.” – Chris Murman"A thoughtfully written book in very straightforward language." – A.L. PeeveyYou can find more reviews on the pages of my other books, such as this one.

This could be interesting as an overview to recommend

It's fairly often that I see a tweet that sums to something like "I find <prevalent concept> super hard" or "everybody's bad at <prevalent concept>, nobody really gets it" and I think it's worth discussing who and what this serves to accomplish

— shelley (@codebytere) September 11, 2020

This, but also and specifically for mathematics! We need to normalize the idea that math is easy.

In mathematics, the tombstone, halmos, end-of-proof, or Q.E.D. symbol "∎" (or "□") is a symbol used to denote the end of a proof, in place of the traditional abbreviation "Q.E.D." for the Latin phrase "quod erat demonstrandum", meaning "which was to be demonstrated". In magazines, it is one of the various symbols used to indicate the end of an article. In Unicode, it is represented as character U+220E ∎ END OF PROOF (HTML ∎). Its graphic form varies, as it may be a hollow or filled rectangle or square.

Hello fellow mathematician!

There are lots of ways to syndicate content, some dependent on which platform(s) you’re using and where you’re syndicating to/from. Your best bet is to swing by the IndieWeb Dev chat and ask that very question.

Theorem: Syndication is easy.

Proof: “It’s easy to show” (I’m waving my hands here) that there are a lot of assumptions and baggage that go with the word “easiest.” ∎

I’ve personally found there’s generally an inverse relationship between ease/simplicity of syndication and control over exact display for most platforms. You could go low-fi and pipe your feed into something like IFTTT/Zapier for cross-posting all the way up to customized integration with available APIs for each platform. Many take a middle-of-the-road approach that I notice Jeremy recommended as I’m writing this.

The cross-posting wiki page will give you some useful terminology and definitions which may help you decide on how to syndicate what/where. Based on the context of the URL in your Twitter profile, the IndieWeb wiki pages for static site generator and syndication will give you some ideas and options to think about and explore.

Some of the pages about specific static site generators will give you some code and ideas for how to implement syndication. For example Max Böck has an article Indieweb pt1: Syndicating Content to Twitter, which is Eleventy and Twitter specific, but which could likely be modified for your purposes. SSGs may have some specific peculiarities for syndication that I’m not as familiar with coming from the more dynamic side of the fence.

Since you indicate a language preference for your current site, there’s also a page for Flask with a few users noted there. You might ask Fluffy (usually around in chat) for some advice as I know she syndicates to a few platforms and may have some ideas or even tools/code to share from the Flask perspective.

Q.E.D., right!?

(p.s.: Great Twitter handle!)

Hagoromo chalk has developed a cult following among mathematicians. When the company went out of business, chaos ensued.

I’ve read this same sort of article in other venues in the past, but closer to the revival of the company. This seems to have cropped up again because the original owner of the Japanese company has passed away in the last month.

The Society for Mathematical Biology - e-Conference 2020.

August 17 - 20, 2020

OK when I can't even figure out how to send a viewer to the top of the page, it's time to get up and go for a ride. #indieweb blues

— Cognitively_Accessible_Math (@geonz) August 6, 2020

IndieWeb, cycling, math, AND OER! I’m in…

How was I not following @geonz before?!

a fast way to write and share mathematics

I LATEXed up lecture notes for many of the classes I have taken; feel free to read through them or use them to review. If you find a mistake or typo, please let me know. If you want to look over the .tex source for any of these notes, please send me an email.

A great set of LaTeXed notes from a variety of coursework.

via Rama Kunapuli.