Cearense, Prof. Universidade de Fortaleza

Fortaleza, Brazil
Joined January 2013
From today, customs duties apply to e-commerce parcels worth up to €150 entering the EU. 30 million Europeans work in retail; it's our our largest private-sector employer. And the surge in low-value online imports has put our retailers at an unfair disadvantage. Too many of these products also fail to meet EU safety standards, putting consumers at risk. Today's change is about restoring fairness for European businesses and better protecting our consumers.
Readers added context they thought people might want to know
In March 2025, Ursula von der Leyen stated: “Tariffs are taxes. They are bad for business, and even worse for consumers.” Today she announced new customs duties on e-commerce parcels valued up to €150, arguing this will protect European retailers and consumers. bbc.com/news/articles/…
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Attention @arxiv authors: Our Code of Conduct states that by signing your name as an author of a paper, each author takes full responsibility for all its contents, irrespective of how the contents were generated. 1/
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Really enjoying the discussion around our latest preprint 😎
Very interesting new study finding that *even in large European cities*, in most places it is easier to access opportunities by car than by public transport arxiv.org/pdf/2604.01019 The exceptions are Paris, Zurich and the innermost parts of Milan and Barcelona
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Hygor Piaget retweeted
Tyler Cowen on Brazil
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Proximity-based cities emit less mobility-driven CO2. "The 15-minute city model promotes active mobility by ensuring that essential services are reachable within a short walk or bike ride from home" F. Marzolla & al In npj Sustainable Mobility &Transport nature.com/articles/s44333-0…
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*Optimal Team Size for a Exploration-Exploitation Problem* hygorpiaget.github.io/explor…
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a world within a world...
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Hygor Piaget retweeted
On Landau's ranking of theoretical physicists. Lev Landau, a Nobelist and one of the fathers of the great Soviet physics system, had a logarithmic scale for ranking theorists, from 1 to 5. A physicist in the first class had ten times the impact of someone in the second class, and so on. He modestly ranked himself as 2.5 until late in life, when he became a 2. In the first class were Heisenberg, Bohr, Dirac, Feynman and some others; Einstein was a 0.5! Landau also ranked theorists based on two criteria: 1. energy, perseverance, tenacity 2. originality and genius He developed a diagrammtic representation of these qualities: #1 proportional to the length of the bottom horizontal line, and #2 inversely proportional to the length of the top horizontal line. See thread below for examples.
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A coloured print of Tycho Brahe’s Uraniborg palace-observatory from his 1598 book. watercolor.
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This animation shows the Gillespie algorithm simulating 50 independent Poisson processes racing along a 1D lattice. Made with #python #numpy #matplotlib
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I did more tests with Google's #Veo3. Imagine if AI characters became aware they were living in a simulation!
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Jim Simons is the only person there who could say the last line 😅 Location: Simons Center #physics #scicomm
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lol who did this
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Renormalisation is a central concept in modern physics. It describes how the dynamics of a system change at different scales. A great way to understand and visualise renormalisation is the Ising model (some math, but one can follow without it ) 1/13
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"he and his wife brainstormed nicer-sounding names.Archive?Already taken. Maybe they could sub in the Greek equivalent of X, chi (pronounced like “kai”). “She wrote it down and crossed out the e to make it more symmetric around the X,” “So arXiv it was.”" wired.com/story/inside-arxiv…
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Replying to @vcastellm
Mindset + eagerness to preserve a life style shaped by cities affording much less population in the past. Even in highly dense ones, there's room for improvement: how amenities are distributed have a big impact! We did a piece relying on this nice paper: nature.com/articles/s44284-0…
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How can we create a more inclusive society? I am proud to share that @CompSysSoc will have an #OpenArmsGrant for @ConfCompSys to support all expenses of researchers from low-income countries. ccs25.cssociety.org/open-arm…
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