Propagation dynamics of Fisher-KPP equation with time delay and free boundaries

Incorporating free boundary into time-delayed reaction-diffusion equations yields a compatible condition that guarantees the well-posedness of the initial value problem. With the KPP type nonlinearity we then establish a vanishing-spreading dichotomy result. Further, when the spreading happens, we show that the spreading speed and spreading profile are nonlinearly determined by a delay-induced nonlocal semi-wave problem. It turns out that time delay slows down the spreading speed.Comment: 38 pages, 0 figure

Cofree Hopf algebras on Hopf bimodule algebras

We investigate a Hopf algebra structure on the cotensor coalgebra associated to a Hopf bimodule algebra which contains universal version of Clifford algebras and quantum groups as examples. It is shown to be the bosonization of the quantum quasi-shuffle algebra built on the space of its right coinvariants. The universal property and a Rota-Baxter algebra structure are established on this new algebra.Comment: 20 page

Notes on nonlocal dispersal equations in a periodic habitat

In this paper, we prove that the solution maps of a large class of nonlocal dispersal equations are $\alpha$-contractions, where $\alpha$ is the Kuratowski measure of noncompactness. Then we give some remarks on the spreading speeds and traveling waves for such evolution equations in a periodic habitat

Bistable Traveling Waves for Monotone Semiflows with Applications

This paper is devoted to the study of traveling waves for monotone evolution systems of bistable type. Under an abstract setting, we establish the existence of bistable traveling waves for discrete and continuous-time monotone semiflows. This result is then extended to the cases of periodic habitat and weak compactness, respectively. We also apply the developed theory to four classes of evolution systems

seasonal influence on age-structured invasive species with yearly generation

How do seasonal successions influence the propagation dynamics of an age-structured invasive species? We investigate this problem by considering the scenario that the offsprings are reproduced in spring and then reach maturation in fall within the same year. For this purpose, a reaction-diffusion system is proposed, with yearly periodic time delay and spatially nonlocal response caused by the periodic developmental process. By appealing to the recently developed dynamical system theories, we obtain the invasion speed $c^*$ and its coincidence with the minimal speed of time periodic traveling waves. The characterizations of $c^*$ suggest that (i) time delay decreases the speed and its periodicity may further do so; (ii) the optimal time to slow down the invasion is the season without juveniles; (iii) the speed increases to infinity with the same order as the square root of the diffusion rate

Quantum effect on luminosity-redshift relation

There are many different proposals for a theory of quantum gravity. Even leaving aside the fundamental difference among theories such as the string theory and the non-perturbative quantum gravity, we are still left with many ambiguities (and/or parameters to be determined) with regard to the choice of variables, the choice of related groups, etc. Loop quantum gravity is also in such a state. It is interesting to search for experimental observables to distinguish these quantum schemes. This paper investigates the loop quantum gravity effect on luminosity-redshift relation. The quantum bounce behavior of loop quantum cosmology is found to result in multivalued correspondence in luminosity-redshift relation. And the detail multivalued behavior can tell the difference of different quantum parameters. The inverse volume quantum correction does not result in bounce behavior in this model, but affects luminosity-redshift relation also significantly.Comment: 11 pages, 3 figures; revised versio

Particle Radiation From Gibbons-Maeda Black Hole

This paper investigates the particle radiation from Gibbons-Maeda black hole. Taking into account the self-gravitation of the particle, we calculate the tunnelling rate of the massless particle across the horizon, then we promote the work to the radiation of the charged particle. The calculations prove that the rate of tunnelling equals precisely the exponent of the difference of the black hole entropy before and after emission and the radiation spectrum deviates from exact thermal. The conclusion supports the viewpoint of information conservation.Comment: 15 pages, no figure

Learning and approximation capability of orthogonal super greedy algorithm

We consider the approximation capability of orthogonal super greedy algorithms (OSGA) and its applications in supervised learning. OSGA is concerned with selecting more than one atoms in each iteration step, which, of course, greatly reduces the computational burden when compared with the conventional orthogonal greedy algorithm (OGA). We prove that even for function classes that are not the convex hull of the dictionary, OSGA does not degrade the approximation capability of OGA provided the dictionary is incoherent. Based on this, we deduce a tight generalization error bound for OSGA learning. Our results show that in the realm of supervised learning, OSGA provides a possibility to further reduce the computational burden of OGA in the premise of maintaining its prominent generalization capability.Comment: 30 pages,14 figure

Learning through deterministic assignment of hidden parameters

Supervised learning frequently boils down to determining hidden and bright parameters in a parameterized hypothesis space based on finite input-output samples. The hidden parameters determine the attributions of hidden predictors or the nonlinear mechanism of an estimator, while the bright parameters characterize how hidden predictors are linearly combined or the linear mechanism. In traditional learning paradigm, hidden and bright parameters are not distinguished and trained simultaneously in one learning process. Such an one-stage learning (OSL) brings a benefit of theoretical analysis but suffers from the high computational burden. To overcome this difficulty, a two-stage learning (TSL) scheme, featured by learning through deterministic assignment of hidden parameters (LtDaHP) was proposed, which suggests to deterministically generate the hidden parameters by using minimal Riesz energy points on a sphere and equally spaced points in an interval. We theoretically show that with such deterministic assignment of hidden parameters, LtDaHP with a neural network realization almost shares the same generalization performance with that of OSL. We also present a series of simulations and application examples to support the outperformance of LtDaH

Optical analogy to quantum Fourier transform based on pseudorandom phase ensemble

In this paper, we introduce an optical analogy to quantum Fourier tanformation based on a pseudorandom phase ensemble. The optical analogy also brings about exponential speedup over classical Fourier tanformation. Using the analogy, we demonstrate three classcial fields to realize Fourier transform similar to three quantum particles.Comment: A small amount of errors modification,16 Pages, 1 figur