scholarly journals Random product of quasi-periodic cocycles

Author(s):  
Jamerson Bezerra ◽  
Mauricio Poletti
Keyword(s):  
2008 ◽  
Vol 45 (04) ◽  
pp. 1161-1180
Author(s):  
Anthony G. Pakes

The upper tail behaviour is explored for a stopped random product ∏j=1NXj, where the factors are positive and independent and identically distributed, andNis the first time one of the factors occupies a subset of the positive reals. This structure is motivated by a heavy-tailed analogue of the factorialn!, called the factoid ofn. Properties of the factoid suggested by computer explorations are shown to be valid. Two topics about the determination of the Zipf exponent in the rank-size law for city sizes are discussed.


2018 ◽  
Vol 29 (2) ◽  
pp. 593-620 ◽  
Author(s):  
Rob Sturman ◽  
Jean-Luc Thiffeault

2021 ◽  
Vol 9 ◽  
Author(s):  
Ruben Poghosyan ◽  
David B. Saakian

We consider the product of a large number of two 2 × 2 matrices chosen randomly (with some correlation): at any round there are transition probabilities for the matrix type, depending on the choice at previous round. Previously, a functional equation has been derived to calculate such a random product of matrices. Here, we identify the phase structure of the problem with exact expressions for the transition points separating “localized” and “ergodic” regimes. We demonstrate that the latter regime develops through a formation of an infinite series of singularities in the steady-state distribution of vectors that results from the action of the random product of matrices on an initial vector.


PRX Quantum ◽  
2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Chi-Fang Chen ◽  
Hsin-Yuan Huang ◽  
Richard Kueng ◽  
Joel A. Tropp

2020 ◽  
Vol 10 (14) ◽  
pp. 4817
Author(s):  
Mirosław Kordos ◽  
Jan Boryczko ◽  
Marcin Blachnik ◽  
Sławomir Golak

We present a complete, fully automatic solution based on genetic algorithms for the optimization of discrete product placement and of order picking routes in a warehouse. The solution takes as input the warehouse structure and the list of orders and returns the optimized product placement, which minimizes the sum of the order picking times. The order picking routes are optimized mostly by genetic algorithms with multi-parent crossover operator, but for some cases also permutations and local search methods can be used. The product placement is optimized by another genetic algorithm, where the sum of the lengths of the optimized order picking routes is used as the cost of the given product placement. We present several ideas, which improve and accelerate the optimization, as the proper number of parents in crossover, the caching procedure, multiple restart and order grouping. In the presented experiments, in comparison with the random product placement and random product picking order, the optimization of order picking routes allowed the decrease of the total order picking times to 54%, optimization of product placement with the basic version of the method allowed to reduce that time to 26% and optimization of product placement with the methods with the improvements, as multiple restart and multi-parent crossover to 21%.


2020 ◽  
Vol 22 (08) ◽  
pp. 1950086
Author(s):  
Edgar Matias ◽  
Ítalo Melo

We present a necessary and sufficient condition for a random product of maps on a compact metric space to be (strongly) synchronizing on average.


2020 ◽  
Vol 9 (6) ◽  
Author(s):  
Shiyu Zhou ◽  
Zhicheng Yang ◽  
Alioscia Hamma ◽  
Claudio Chamon

Clifford circuits are insufficient for universal quantum computation or creating tt-designs with t\ge 4t≥4. While the entanglement entropy is not a telltale of this insufficiency, the entanglement spectrum of a time evolved random product state is: the entanglement levels are Poisson-distributed for circuits restricted to the Clifford gate-set, while the levels follow Wigner-Dyson statistics when universal gates are used. In this paper we show, using finite-size scaling analysis of different measures of level spacing statistics, that in the thermodynamic limit, inserting a single T (\pi/8)(π/8) gate in the middle of a random Clifford circuit is sufficient to alter the entanglement spectrum from a Poisson to a Wigner-Dyson distribution.


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