A note on limiting infisup theorems

We show that the limiting infisup theorem of Blair, Duffin and Jeroslow (1982) is a consequence of the classical bifunctional duality. By doing so we generalize their results and prove another limiting infisup theorem for convex quasi-concave functions.     

A note on perfect duality and limiting lagrangeans

In this note we derive and extend the substance of recent results on Perfect Duality and Limiting Lagrangeans by using standard convex analysis and convex duality theory.Research partially supported by NRC A4493.     

Comments on Global convergence of the method of shortest residuals by Y. Dai and Y. Yuan

Summary. We show that the example given in [Dai, Y., Yuan, Y. (1999): Global convergence of the method of shortest residuals, Numerische Mathematik 83, 581–598] does not contradict the results of [Pytlak, R. (1994): On the convergence of conjugate gradient algorithms, IMA J. Numerical Analysis 14, 443–460]. Received September 9, 2000 / Revised version received November 28, 2000 / Published online July 25, 2001     

A Note on “State Spaces of the Snake and Its Tour—Convergence of the Discrete Snake” by J.-F. Marckert and A. Mokkadem

In State spaces of the snake and its tour—Convergence of the discrete snake the authors showed a limit theorem for Galton–Watson trees with geometric offspring distribution. In this note it is shown that their result holds for all Galton–Watson trees with finite offspring variance.     

A note on the theorems of M.G. Krein and L.A. Sakhnovich on continuous analogs of orthogonal polynomials on the circle

Continuous analogs of orthogonal polynomials on the circle are solutions of a canonical system of differential equations, introduced and studied by Krein and recently generalized to matrix systems by Sakhnovich. We prove that the continuous analogs of the adjoint polynomials converge in the upper half-plane in the case of L² coefficients, but in general the limit can be defined only up to a constant multiple even when the coefficients are in L^p for any p>2, the spectral measure is absolutely continuous and the Szegö-Kolmogorov-Krein condition is satisfied. Thus, we point out that Krein's and Sakhnovich's papers contain an inaccuracy, which does not undermine known implications from these results.     

A note on a question of J. Nekovár and the Birch and Swinnerton-Dyer conjecture

If is a square-free integer, then let denote the elliptic curve over given by the equation

Let denote the Hasse-Weil -function of , and let denote the `algebraic part' of the central critical value . Using a theorem of Sturm, we verify a congruence conjectured by J. Neková\v{r}. By his work, if denotes the 3-Selmer group of and is a square-free integer with , then we find that

     

Slice filtration on motives and the Hodge conjecture (with an appendix by J. Ayoub)

We clarify the expected properties of the slice filtration on triangulated motives from the point of view of the generalized Hodge conjecture. In the appendix, J. Ayoub proves unconditionally that the slice filtration does not respect geometric motives. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Comments on “On stability of switched homogeneous nonlinear systems” by Lijun Zhang, Sheng Liu, and Hai Lan [J. Math. Anal. Appl. 334 (1) (2007) 414-430]

We show that the proof of the results obtained in the above paper is wrong since it is based on lemma which is not true. Therefore the results of the paper cannot be considered as true ones.     

Some remarks on “On the windowed Fourier transform and wavelet transform of almost periodic functions,” by J.R. Partington and B. Ünalmı

J.R. Partington and B. Ünalmı consider in their 2001 paper [J.R. Partington, B. Ünalmı , Appl. Comput. Harmon. Anal. 10 (1) (2001) 45–60] the windowed Fourier transform and wavelet transform as tools for analyzing almost periodic signals. They establish Parseval-type identities and consider discretized versions of these transforms in order to construct generalized frame decompositions. We have found a gap in the construction of generalized frames in the windowed Fourier transform case; we comment on this gap and give an alternative proof. As for the wavelet transform case, in [J.R. Partington, B. Ünalmı , Appl. Comput. Harmon. Anal. 10 (1) (2001) 45–60] the generalized frame decomposition is done only for the simplest wavelet, the Haar wavelet; we show how to construct generalized frame decompositions for a wide family of wavelets.     

A note on the paper ‘Analytical approach to heat and mass transfer in MHD free convection from a moving permeable vertical surface’ by A. Asgharian,D.D. Ganji,S. Soleimani,S. Asgharian,N. Sedaghatyzade and B. Mohammadi,Mathematical Methods in the Applied Sciences, 2011, 34 2209‐2217

The present note presents some errors in the aforementioned paper published in Mathematical Methods in the Applied Sciences. Two errors are found in the definition of the non‐dimensional parameters and correct results are presented for temperature profiles included in figure 10 of the previous paper. Copyright © 2014 John Wiley & Sons, Ltd.