# Posts

### July 30, 2014

### July 29, 2014

### July 28, 2014

### July 27, 2014

*Basic Category Theory*

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10:14 PM | Bangalore workshop [ಬೆಂಗಳೂರು ಕಾರ್ಯಾಗಾರ]

Second day at the Indo-French Centre for Applied Mathematics and the workshop. Maybe not the most exciting day in terms of talks (as I missed the first two plenary sessions by (a) oversleeping and (b) running across the campus!). However I had a neat talk with another conference participant that led to [what I think […]

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http://alexyar.tumblr.com/post/93267129477/shadowpeoplearejerks-alexyar-anyone-has-good: alexyar:
shadowpeoplearejerks:
shadowpeoplearejerks:
alexyar:
shadowpeoplearejerks:
alexyar:
Anyone has good references for learning characteristic classes?
Milnor is the classic reference.
Ok so here’s a thing: we’re running a geometry/topology proseminar with a couple of people in the department, and “Characteristic classes” is our topic…
That’s actually why I can’t read that book
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This is the 7th (continuing from part I and part II and part III and part IV and part V and part VI) in a series of expository posts where we put together in one place the pieces from various places about: how is treated lambda calculus in chemlambda how it works, with special emphasis […]

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8:56 AM | Mathgate

Mathgate declares its purpose as a “website for learning logic and mathematics through formal proofs”. The author and owner of Mathgate is Chad E. Brown, who is also the author of Satallax – an automated theorem prover which has won a a couple of times on the CADE ATP Systems Competition. Mathgate is powered by […]

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Note to self: check Jack Morava’s arXiv notes on a more regular basis! It started with the G+-post below by +David Roberts: Suddenly I realised I hadn’t checked out Morava‘s “short preprints with ambitious ideas, but no proofs” lately. A couple of years ago I had a brief email exchange with him on the Habiro ...

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6:08 AM | Bangalore workshop [ಬೆಂಗಳೂರು ಕಾರ್ಯಾಗಾರ]

First day at the Indo-French Centre for Applied Mathematics and the get-together (or speed-dating!) workshop. The campus of the Indian Institute of Science of Bangalore where we all stay is very pleasant with plenty of greenery in the middle of a very busy city. Plus, being at about 1000m means the temperature remains tolerable for […]

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10:21 PM | Number Theory, the African Queen

“Mathematics is the queen of the sciences and number theory is the queen of mathematics.” - Carl Friederich Gauss. This month, I had the incredible honor of teaching at a summer school on “Algebraic Number Theory and Applications” in Dangbo, Benin. It was a unique opportunity, … Continue reading →

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Here is a question I raised at the Puerto-Rico conference during one of the “problem sessions.” Toby Gee seems to remember that I had some half-baked heuristics that predicted both A and B below, but perhaps one of my readers … Continue reading →

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6:27 PM | Stacks incubator?

Here is the idea (stolen from the cring project): collect any expository notes written by you and put them on the web under the GFDL. Why? I have several reasons: I have many times come across good expositions by younger … Continue reading →

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8:28 AM | A confused sleeping beauty

The Sleeping Beauty problem A recent post by Sean Carroll reignited a debate about the "Sleeping beauty problem".This is a simple problem of probabilities, involving tossing a coin. But for some reason, it seems to be no agreement about its solution.Consider the following experiment:- On Sunday, put Sleeping Beauty to sleep.- Toss a fair coin.- We are interested to ask Sleeping Beauty the question Q. What is your belief now for the proposition that the coin landed heads? - If the coin
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It’s probably much too late for this, but the heart of the (geometric) analogy between circular and hyperbolic trigonometric functions is that circles and hyperbolas have internal symmetries visibly parametrized by a geometric area.
Now, obviously there are things the analogy does not capture, and there are things that obscure the analogy. For instance, the hyperbolic symmetry (which is a genuine symmetry!) does not play nice with the ordinary lengths of things in the plane; however, my
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10:14 PM | Bangalore snapshot [ಬೆಂಗಳೂರು ಚಿತ್ರ]

Filed under: pictures, Travel Tagged: Bangalore, India, Kannada, Karnataka, KR Market, storm

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8:33 PM | Particelle familiari

Recensione breve: ho letto il libro Particelle familiari di Marco Delmastro e mi è piaciuto, leggetelo.Recensione lunga: Marco Delmastro è un fisico che lavora a ATLAS, uno degli esperimenti del CERN che ha osservato il (un?) bosone di Higgs. In questo libro racconta cosa fa un fisico sperimentale, come fa a osservare particelle così piccole e elusive che anche solo il termine "osservare" assume significati nuovi.Il libro è dedicato a chi non sa niente di fisica e vorrebbe saperne qualcosa […]

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There are not many women in the french Académie des Sciences. So it was a great news when last december Laure Saint-Raymond got elected (in the mechanics section, due to her work on physics equations, rather than in the math section). Today, there’s a portrait of her on the backpage of Libération (a nationwide french […]

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1:40 PM | one hundred years ago, a telegram…

Filed under: Books, Kids, pictures Tagged: Austro-Hungary, Frist World War, Serbia, telegram, war

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Alerted by the post Episciences.org progress by Thomas Arildsen, I took a look at the EPI-IAM and I discovered something to be appreciated. Indeed, compare the non-combat stance of Episciences.org The project proposes an alternative to existing economic models, without competing with traditional publishers. with the one of EPI-IAM: The driving force for this project […]

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3:18 AM | stop or i’ll say stop again

http://kitchentablemath.blogspot.com/2014/07/elizabeth-green-is-funded-by-bill-gates.html

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10:14 PM | PMC for combinatoric spaces

I received this interesting [edited] email from Xiannian Fan at CUNY: I am trying to use PMC to solve Bayesian network structure learning problem (which is in a combinatorial space, not continuous space). In PMC, the proposal distributions qi,t can be very flexible, even specific to each iteration and each instance. My problem occurs due […]

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Approximately a year ago I wrote the post A chemical concrete machine for lambda calculus. Quote: How can this be done? Here is sketch, mind you that I propose things which I believe are possible from a chemical perspective, but I don’t have any chemistry knowledge. If you do, and if you are interested to […]

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12:18 PM | off to Bangalore [#2]

While I was trying to find a proper window to take a picture of the mountains of Eastern Turkey, an Air France flight attendant suggested me to try the view from the pilots’ cockpit! I thought she was joking but, after putting a request to the captain, she came to walk me there and I […]

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11:07 AM | Higher order reflections

Mathematical reflections, not those supposedly practiced in metaphilosophy. Given a function defined for , we have two basic ways to reflect it about : even reflection and odd reflection . Here is the even reflection of the exponential function : The extended function is not differentiable at . The odd reflection, pictured below, is not […]

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10:17 PM | Ulam’s grave [STAN post]

Since Stan Ulam is buried in Cimetière du Montparnasse, next to CREST, Andrew and I paid his grave a visit on a sunny July afternoon. Among elaborate funeral constructions, the Aron family tomb is sober and hidden behind funeral houses. It came as a surprise to me to discover that Ulam had links with France […]

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10:00 PM | Souvenirs from Amsterdam

(I am writing a post on hot trends in mathematics in the midst of war, completely ignoring it. This seems like the wrong thing to do, but my urge to write has overcome me. To any reader of this blog: I wish you a peaceful night, wherever you are). Last week I returned from the yearly […]

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7:17 PM | Gaussianos cumple 8 años de vida

En el día de hoy, 26 de julio de 2014, Gaussianos cumple 8 años de vida. Este mismo día, en 2006, nacía este blog con el objetivo de acercar un poco las matemáticas a todos los internautas, y parece mentira que hayamos conseguido mantenernos por aquí tanto tiempo. La verdad es que este octavo año […]Entra en Gaussianos si quieres hacer algún comentario sobre este artículo, consultar entradas anteriores o enviarnos un mensaje.Construye tú también el
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via @CERN http://t.co/9Rac42mBVh #CPviolation #CPsymmetry #matter #antimatter The CP violation is a violation of the CP-symmetry, a combination between the charge conjugation symmetry (C) and the parity symmetry (P). CP-symmetry states that the laws of physics should be the same if a particle is interchanged with its antiparticle, and then its spatial coordinates are inverted.The CP violation is discovered in 1964 by Christenson, Cronin, Fitch, and Turlay (Cronin and Fitch awarded the Nobel […]

Christenson, J., Cronin, J., Fitch, V. & Turlay, R. (1964). Evidence for the 2π Decay of the K_{2}^{0} Meson, Physical Review Letters, 13 (4) 138-140. DOI: 10.1103/PhysRevLett.13.138

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by @ulaulaman http://t.co/Q3AODpvKAs #Godel #ontologicalproof #god #computer The ontological arguments for the existence of God was introduced for the first time by St. Anselm in 1078: God, by definition, is that for which no greater can be conceived. God exists in the understanding. If God exists in the understanding, we could imagine Him to be greater by existing in reality. Therefore, God must exist.There are a lot of phylosophies, mathematics and logicians that proposed their ontological […]

Christoph Benzmüller & Bruno Woltzenlogel Paleo (2013). Formalization, Mechanization and Automation of Gödel's Proof of God's Existence, arXiv: 1308.4526v4

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\[(n+1)^3 - n^3 \equiv 1 \mod 6\] Claudi Alsina,, Roger Nelsen,, & Hasan Unal (2014). Proof Without Words: The Difference of Consecutive Integer Cubes Is Congruent to 1 Modulo 6 The College Mathematics Journal, 45 (2), 135-135 DOI: 10.4169/college.math.j.45.2.135 (facebook)

Claudi Alsina,, Roger Nelsen, & Hasan Unal (2014). Proof Without Words: The Difference of Consecutive Integer Cubes Is Congruent to 1 Modulo 6, The College Mathematics Journal, 45 (2) 135-135. DOI: 10.4169/college.math.j.45.2.135

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\[(n+1)^3 - n^3 \equiv 1 \mod 6\] Claudi Alsina,, Roger Nelsen,, & Hasan Unal (2014). Proof Without Words: The Difference of Consecutive Integer Cubes Is Congruent to 1 Modulo 6 The College Mathematics Journal, 45 (2), 135-135 DOI: 10.4169/college.math.j.45.2.135 (facebook)...
Claudi Alsina,, Roger Nelsen,, & Hasan Unal. (2014) Proof Without Words: The Difference of Consecutive Integer Cubes Is Congruent to 1 Modulo 6. The College Mathematics Journal, 45(2), 135-135.
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Claudi Alsina,, Roger Nelsen, & Hasan Unal (2014). Proof Without Words: The Difference of Consecutive Integer Cubes Is Congruent to 1 Modulo 6, The College Mathematics Journal, 45 (2) 135-135. DOI: 10.4169/college.math.j.45.2.135

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La settimana scorsa, su twitter, ho diffuso alcune immagini, foto scattate dalle pagine dal volume Letture da Le Scienze: Fisica delle particelle (un indice del volume), che raccoglieva alcuni articoli usciti sulla rivista italiana (e quindi anche su Scientific American). Poiché ognuna di quelle immagini fa inevitabilmente parte della storia della fisica, mi sembra sensato proporle raccolte insieme in un unico post molto più semplicemente raggiungibile di tanti piccoli... cinguettii.
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Weisskopf, V. (1968). The Three Spectroscopies, Scientific American, 218 (5) 15-29. DOI: 10.1038/scientificamerican0568-15

Barish, B. (1973). Experiments with Neutrino Beams, Scientific American, 229 (2) 30-38. DOI: 10.1038/scientificamerican0873-30

Treiman, S. (1959). The Weak Interactions, Scientific American, 200 (3) 72-84. DOI: 10.1038/scientificamerican0359-72

Cline D.B., Mann A.K. & Rubbia C. (1974). The Detection of Neutral Weak Currents, Scientific American, 231 (6) 108-119. DOI: 10.1038/scientificamerican1274-108

Glashow, S. (1975). Quarks with Color and Flavor, Scientific American, 233 (4) 38-50. DOI: 10.1038/scientificamerican1075-38

Nambu, Y. (1976). The Confinement of Quarks, Scientific American, 235 (5) 48-61. DOI: 10.1038/scientificamerican1176-48

Johnson, K. (1979). The Bag Model of Quark Confinement, Scientific American, 241 (1) 112-121. DOI: 10.1038/scientificamerican0779-112

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MindAfterMath tweeted: @MindAfterMath

2014-07-31 08:57:58

ulaulaman tweeted: @ulaulaman

Le Olimpiadi di Matematica stimolano la creatività: Intervista di @maddmaths al due volte medaglia d'oro Dario Ascari http://t.co/nyRPxzYcZi

2014-07-31 08:55:51

ulaulaman tweeted: @ulaulaman

Archimede e @maddmaths: due iniziative parallele per discutere della prova di matematica alla Maturità http://t.co/rk9RHukzhu

2014-07-31 08:51:05

jamesgrime tweeted: @jamesgrime

RT @Cumberbatch_Fr: Traduction de l'analyse du trailer UK de #TIG par @jamesgrime expert de Turing celle du trailer US arrive très vite! ht…

2014-07-31 08:30:54

freakonometrics tweeted: @freakonometrics

ScratchJr http://t.co/nlocNiumRB see http://t.co/uHLGJmbHQj (really want to try...)

2014-07-31 08:09:25

Quasilocal tweeted: @Quasilocal

@chiochia To be honest, I had a massive brain-fart and briefly forgot hadrons even existed (I need more sleep). Pretty cool though

2014-07-31 07:38:01

wpgaurav tweeted: @wpgaurav

Google's Global Science Fair is on - Sign Up Now http://t.co/3y6xlZm6At

2014-07-31 07:19:27

MindAfterMath tweeted: @MindAfterMath

2014-07-31 06:57:49

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