Search results for "Mathematica"
showing 10 items of 7971 documents
A counterexample to Feit's Problem VIII on decomposition numbers
2016
We find a counterexample to Feit's Problem VIII on the bound of decomposition numbers. This also answers a question raised by T. Holm and W. Willems.
Character restrictions and multiplicities in symmetric groups
2017
Abstract We give natural correspondences of odd-degree characters of the symmetric groups and some of their subgroups, which can be described easily by restriction of characters, degrees and multiplicities.
THE ZONE MODULUS OF A LINK
2005
In this paper, we construct a conformally invariant functional for two-component links called the zone modulus of the link. Its main property is to give a sufficient condition for a link to be split. The zone modulus is a positive number, and its lower bound is 1. To construct a link with modulus arbitrarily close to 1, it is sufficient to consider two small disjoint spheres each one far from the other and then to construct a link by taking a circle enclosed in each sphere. Such a link is a split link. The situation is different when the link is non-split: we will prove that the modulus of a non-split link is greater than [Formula: see text]. This value of the modulus is realized by a spec…
On the automorphism group of the integral group ring of Sk wr Sn
1992
Abstract Let G = SkwrSn be the wreath product of two symmetric groups Sk and Sn. We prove that every normalized automorphism θ of the integral group ring Z G can be written in the form θ = γ ° τu, where γ is an automorphism of G and τu denotes the inner automorphism induced by a unit u in Q G.
A STUDY OF THE πN SCATTERING DATA WITH JP = 3/2- AND A PROOF OF THE EXISTENCE OF THE N*(1700)
2014
Using an interaction extracted from the local hidden gauge Lagrangians and the coupled channels ρN (s-wave), πN (d-wave), πΔ (s-wave) and πΔ (d-wave), we look in the region of [Formula: see text] and we find two resonances dynamically generated which are naturally associated to the N*(1520)(3/2-) and N*(1700)(3/2-). The N*(1700)(3/2-) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the πN (d-wave) data. The unitary coupled channel approach followed here, in connection with the experimental data, leads automatically to a pole in the 1700 MeV region and makes this second 3/2- resonance unavoidable.
Zur Existenz von Lösungen gewisser Randwertaufgaben
1971
With the aid of some known results about integral equations of the Hammerstein type there is proofed an existence theorem for the following class of boundary value problems−y″−l 2 y′=f(x,y),y(a)=y(b)=0,l 2>0 mit|f(x, y)|=0,l 3 (x)>0. The existence range is determined by the greatest eigenvalue of some linear problem.
Reduction of a Non—Linear Parabolic Initial—Boundary Value Problem to Cauchy Problem for a System of ODEs
2004
We consider the boundary value problem for a parabolic equation in the form $$\frac{{\partial {\text{u}}}}{{\partial t}} = \frac{1}{{p(x)}}\frac{\partial }{{\partial x}}\left( {p(x)f'(u)\frac{{\partial u}}{{\partial x}}} \right) + F(u),x \in (0,l),t0,$$ (1) $$u(0,x) = {u_0}(x),$$ (2) $$\frac{{\partial u}}{{\partial x}}{|_{x = 0}} = {f_1}\left( {{u_1}} \right),$$ (3) $$\frac{{\partial u}}{{\partial x}}{|_{x = 1}} = {f_2}\left( {{u_2}} \right),$$ (4) where u = u(t,x) is the unknown function, f 1, f 2, F, f are nonlinear functions and f′ (u) > 0, $${u_1} = {u_1}\left( t \right) \equiv u\left( {t,0} \right),{u_2} = {u_2}(t) \equiv u\left( {t,l} \right),f'\left( u \right) \equiv df(u)/du,p(x) \g…
On the Second Order Rational Difference Equation $$x_{n+1}=\beta +\frac{1}{x_n x_{n-1}}$$ x n + 1 = β + 1 x n x n - 1
2016
The author investigates the local and global stability character, the periodic nature, and the boundedness of solutions of the second-order rational difference equation $$x_{n+1}=\beta +\frac{1}{x_{n}x_{n-1}}, \quad n=0,1,\ldots ,$$ with parameter \(\beta \) and with arbitrary initial conditions such that the denominator is always positive. The main goal of the paper is to confirm Conjecture 8.1 and to solve Open Problem 8.2 stated by A.M. Amleh, E. Camouzis and G. Ladas in On the Dynamics of a Rational Difference Equations I (International Journal of Difference Equations, Volume 3, Number 1, 2008, pp.1–35).
Classification générique de synthèses temps minimales avec cible de codimension un et applications
1997
In this article we consider the problem of constructing the optimal closed loop control in the time minimal control problem, with terminal constraints belonging to a manifold of codimension one, for systems of the form v = X + uY, v ϵ R2, R3, |u| ≤ 1 under generic assumptions. The analysis is localized near the terminal manifold and is motivated by the problem of controlling a class of chemical systems.
Co-learnability and FIN-identifiability of enumerable classes of total recursive functions
1994
Co-learnability is an inference process where instead of producing the final result, the strategy produces all the natural numbers but one, and the omitted number is an encoding of the correct result. It has been proved in [1] that co-learnability of Goedel numbers is equivalent to EX-identifiability. We consider co-learnability of indices in recursively enumerable (r.e.) numberings. The power of co-learnability depends on the numberings used. Every r.e. class of total recursive functions is co-learnable in some r.e. numbering. FIN-identifiable classes are co-learnable in all r.e. numberings, and classes containing a function being accumulation point are not co-learnable in some r.e. number…