Data analytics are changing the ways to judge the influence of papers and journals.
The base question is are citations the best indicator of impact, or are there other better emerging methods of indicating the impact of scholarly work?
Data analytics are changing the ways to judge the influence of papers and journals.
The base question is are citations the best indicator of impact, or are there other better emerging methods of indicating the impact of scholarly work?
From hiccups to wisdom teeth, our own bodies are worse off than most because of the differences between the wilderness in which we evolved and the modern world in which we live.
The chessboard is the world; the pieces are the phenomena of the universe; the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us. We know that his play is always fair, just, and patient. But also we know, to our cost, that he never overlooks a mistake or makes the smallest allowance for ignorance.
At TEDGlobal 2010, author Matt Ridley shows how, throughout history, the engine of human progress has been the meeting and mating of ideas to make new ideas. It's not important how clever individuals are, he says; what really matters is how smart the collective brain is.
…[the reader] should not be discouraged, if on first reading of section 0, he finds that he does not have the prerequisites for reading the prerequisites.
This is essentially the mathematician’s equivalent of the adage “Fake it ’til you make it.”
A well-trained man knows how to answer questions; an educated man knows what questions are worth asking.
Q: When did Nicholas Bourbaki quit writing books about mathematics?
A: When (t)he(y) realized that Serge Lang was only one person!
Abstract
This is a brief announcement of our recent proof of global existence and rapid decay to equilibrium of classical solutions to the Boltzmann equation without any angular cutoff, that is, for long-range interactions. We consider perturbations of the Maxwellian equilibrium states and include the physical cross-sections arising from an inverse-power intermolecular potential r-(p-1) with p > 2, and more generally. We present here a mathematical framework for unique global in time solutions for all of these potentials. We consider it remarkable that this equation, derived by Boltzmann (1) in 1872 and Maxwell (2) in 1867, grants a basic example where a range of geometric fractional derivatives occur in a physical model of the natural world. Our methods provide a new understanding of the effects due to grazing collisions.
In the last two years, at least 10 law schools have made their grading systems more lenient to give their students a better chance in a soft job market.
Is GPA tampering and grade inflation going too far with changes like this?
Even by the standards of continuum functional integrals we have hit a new low…
He really has a great sense of humor, doesn’t he?
For the first time in the United States, stem cells have been directly injected into the spinal cord of a patient, researchers announced Thursday.
As a separate note, who really wants to waste the time building thousands and thousands of followers when none of them are really going to ever pay attention to you? Yes, it’s great to have a high number, but really what is your ultimate reach? How many people are you engaging?
Degradable quantum channels are among the only channels whose quantum and private classical capacities are known. As such, determining the structure of these channels is a pressing open question in quantum information theory. We give a comprehensive review of what is currently known about the structure of degradable quantum channels, including a number of new results as well as alternate proofs of some known results. In the case of qubits, we provide a complete characterization of all degradable channels with two dimensional output, give a new proof that a qubit channel with two Kraus operators is either degradable or anti-degradable, and present a complete description of anti-degradable unital qubit channels with a new proof. For higher output dimensions we explore the relationship between the output and environment dimensions (dB and dE, respectively) of degradable channels. For several broad classes of channels we show that they can be modeled with an environment that is “small” in the sense of ΦC. Such channels include all those with qubit or qutrit output, those that map some pure state to an output with full rank, and all those which can be represented using simultaneously diagonal Kraus operators, even in a non-orthogonal basis. Perhaps surprisingly, we also present examples of degradable channels with “large” environments, in the sense that the minimal dimension dE>dB. Indeed, one can have dE>14d2B. These examples can also be used to give a negative answer to the question of whether additivity of the coherent information is helpful for establishing additivity for the Holevo capacity of a pair of channels. In the case of channels with diagonal Kraus operators, we describe the subclasses that are complements of entanglement breaking channels. We also obtain a number of results for channels in the convex hull of conjugations with generalized Pauli matrices. However, a number of open questions remain about these channels and the more general case of random unitary channels.