A Logic of Multi-Level Change of Routines

This paper tries to account for endogenous change of multi-level routines in terms of nested cycles of discovery, in a hierarchy of scripts.Higher-level scripts constitute the selection environment for lower level ones.On any level, a cycle of discovery proceeds from established dominant designs.When subjected to new conditions, a script first tries to adapt by proximate change, in differentiation, with novel selection of subscripts in existing nodes in existing script architecture.Next, in reciprocation it adopts new nodes from other, surrounding scripts.Next, it adapts script architecture, in novel configurations of old and new nodes.In this way, lower level change of subscripts can force higher-level change of superscripts.In this way, institutions may co-evolve with innovation.routines;learning;evolution

Speaking Stata: How to move step by: step

The by varlist: construct is reviewed, showing how it can be used to tackle a variety of problems with group structure. These range from simply doing some calculations for each of several groups of observations to doing more advanced manipulations making use of the fact that with this construct, subscripts and the built-ins _n and _N are all interpreted within groups. A fairly complete tutorial on numerical evaluation of true and false conditions is included. Copyright 2002 by Stata Corporation.by, sorting, subscripts, true and false

The Ryu-Takayanagi Formula from Quantum Error Correction

I argue that a version of the quantum-corrected Ryu-Takayanagi formula holds in any quantum error-correcting code. I present this result as a series of theorems of increasing generality, with the final statement expressed in the language of operator-algebra quantum error correction. In AdS/CFT this gives a "purely boundary" interpretation of the formula. I also extend a recent theorem, which established entanglement-wedge reconstruction in AdS/CFT, when interpreted as a subsystem code, to the more general, and I argue more physical, case of subalgebra codes. For completeness, I include a self-contained presentation of the theory of von Neumann algebras on finite-dimensional Hilbert spaces, as well as the algebraic definition of entropy. The results confirm a close relationship between bulk gauge transformations, edge-modes/soft-hair on black holes, and the Ryu-Takayanagi formula. They also suggest a new perspective on the homology constraint, which basically is to get rid of it in a way that preserves the validity of the formula, but which removes any tension with the linearity of quantum mechanics. Moreover they suggest a boundary interpretation of the "bit threads" recently introduced by Freedman and Headrick.Comment: 40 pages plus appendix, 11 figures, many subscripts on subscripts. v2: Minor corrections and improvements, section 6.3 revised more substantially for clarity, section 6.4 added to discuss some limitation

The number of terms in the permanent and the determinant of a generic circulant matrix

Let A=(a_(ij)) be the generic n by n circulant matrix given by a_(ij)=x_(i+j), with subscripts on x interpreted mod n. Define d(n) (resp. p(n)) to be the number of terms in the determinant (resp. permanent) of A. The function p(n) is well-known and has several combinatorial interpretations. The function d(n), on the other hand, has not been studied previously. We show that when n is a prime power, d(n)=p(n). The proof uses symmetric functions.Comment: 6 pages; 1 figur

Universal amplitude ratios in the 3D Ising Universality Class

We compute a number of universal amplitude ratios in the three-dimensional Ising universality class. To this end, we perform Monte Carlo simulations of the improved Blume-Capel model on the simple cubic lattice. For example, we obtain A_+/A_-=0.536(2) and C_+/C_-=4.713(7), where A_+- and C_+- are the amplitudes of the specific heat and the magnetic susceptibility, respectively. The subscripts + and - indicate the high and the low temperature phase, respectively. We compare our results with those obtained from previous Monte Carlo simulations, high and low temperature series expansions, field theoretic methods and experiments.Comment: 18 pages, two figures, typos corrected, discussion on finite size corrections extende

A Ces\`aro Average of Goldbach numbers

Let $\Lambda$ be the von Mangoldt function and $(r_G(n) = \sum_{m_1 + m_2 = n} \Lambda(m_1) \Lambda(m_2))$ be the counting function for the Goldbach numbers. Let $N \geq 2$ be an integer. We prove that $$\begin{align} &\sum_{n \le N} r_G(n) \frac{(1 - n/N)^k}{\Gamma(k + 1)} = \frac{N^2}{\Gamma(k + 3)} - 2 \sum_\rho \frac{\Gamma(\rho)}{\Gamma(\rho + k + 2)} N^{\rho+1}\\ &\qquad+ \sum_{\rho_1} \sum_{\rho_2} \frac{\Gamma(\rho_1) \Gamma(\rho_2)}{\Gamma(\rho_1 + \rho_2 + k + 1)} N^{\rho_1 + \rho_2} + \mathcal{O}_k(N^{1/2}), \end{align}$$ for $k > 1$, where $\rho$, with or without subscripts, runs over the non-trivial zeros of the Riemann zeta-function $\zeta(s)$.Comment: submitte