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Related papers: Sharp inequalities for the psi function and harmon…

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Biharmonic maps are the critical points of the bienergy functional and, from this point of view, generalise harmonic maps. We consider the Hopf map $\psi:\s^3\to \s^2$ and modify it into a nonharmonic biharmonic map $\phi:\s^3\to \s^3$. We…

Differential Geometry · Mathematics 2007-05-23 E. Loubeau , C. Oniciuc

In this paper, we establish several improved Caffarelli-Kohn-Nirenberg and Hardy-type inequalities. Our main results are divided into two parts. In the first part, we consider the following Caffarelli-Kohn-Nirenberg inequality:…

Analysis of PDEs · Mathematics 2026-01-23 Yuxuan Zhou , Wenming Zou

We prove some isoperimetric type inequalities for real harmonic functions in the unit disk belonging to the Hardy space $h^p$, $p>1$ and for complex harmonic functions in $h^4$. The results extend some recent results on the area. Further we…

Complex Variables · Mathematics 2017-01-13 David Kalaj , Elver Bajrami

This paper determines the sharp asymptotic order of the following reverse H\"older inequality for spherical harmonics $Y_n$ of degree $n$ on the unit sphere $\mathbb{S}^{d-1}$ of $\mathbb{R}^d$ as $n\to \infty$:…

Classical Analysis and ODEs · Mathematics 2014-08-11 Feng Dai , Han Feng , Sergey Tikhonov

In this paper, we extend the Hermite-Hadamard type $\dot{I}$scan inequality to the class of symmetrized harmonic convex functions. The corresponding version for harmonic h-convex functions is also investigated. Furthermore, we establish…

Classical Analysis and ODEs · Mathematics 2017-11-23 Shanhe Wu , Basharat Rehman Ali , Imran Abbas Baloch , Absar Ul Haq

A sharp isoperimetric inequality for the Hamming cube is proved at the critical exponent $\beta=\frac12$. This follows up on previous work, where such bounds were established for $\beta$ near $\frac12$. As a consequence, this result settles…

Classical Analysis and ODEs · Mathematics 2026-02-25 Polona Durcik , Paata Ivanisvili , Joris Roos , Xinyuan Xie

In this paper we prove an isoperimetric inequality for holomorphic functions in the unit polydisc $\mathbf U^n$. As a corollary we derive an inclusion relation between weighted Bergman and Hardy spaces of holomorphic functions in the…

Complex Variables · Mathematics 2014-03-04 Marijan Markovic

In this note we give a new proof of the sharp constant $C = e^{-1/2} + \int_0^1 e^{-x^2/2}\,dx$ in the weak (1, 1) inequality for the dyadic square function. The proof makes use of two Bellman functions $\mathbb{L}$ and $\mathbb{M}$ related…

Classical Analysis and ODEs · Mathematics 2018-12-21 Irina Holmes , Paata Ivanisvili , Alexander Volberg

In this paper, we investigate the complete monotonicity of some functions involving gamma function. Using the monotonic properties of these functions, we derived some inequalities involving gamma and beta functions. Such inequalities…

Classical Analysis and ODEs · Mathematics 2017-06-08 M. Al-Jararha

We establish some inequalities of Schwarz-Pick type for harmonic and hyperbolic harmonic functions on the unit ball of and we disprove a recent conjecture of Liu [Schwarz-Pick Lemma for Harmonic Functions, International Mathematics Research…

Analysis of PDEs · Mathematics 2021-11-05 Adel Khalfallah , Bojana Purtić , Miodrag Mateljević

We obtain sharp two-sided inequalities between $L^p-$norms $(1<p<\infty)$ of functions $Hf$ and $H^*f$, where $H$ is the Hardy operator, $H^*$ is its dual, and $f$ is a nonnegative measurable function on $(0,\infty).$ In an equivalent form,…

Classical Analysis and ODEs · Mathematics 2012-06-11 Viktor Kolyada

In this paper, we study the $(s, C(s))$-Harnack inequality in a domain $G\subset \mathbb{R}^n$ for $s\in(0,1)$ and $C(s)\geq1$ and present a series of inequalities related to $(s, C(s))$-Harnack functions and the Harnack metric. We also…

Complex Variables · Mathematics 2024-12-11 Rahim Kargar

For each value of $p$ such that $0<p<1$, we give a specific example of two functions in the Hardy space $H^p$ and in the Bergman space $A^p$ that do not satisfy the triangle inequality. For Hardy spaces, this provides a much simpler proof…

Complex Variables · Mathematics 2024-08-05 Iván Jiménez , Dragan Vukotić

Originally motivated by a stability problem in Fluid Mechanics, we study the spectral and pseudospectral properties of the differential operator $H_\epsilon = -\partial_x^2 + x^2 + i\epsilon^{-1}f(x)$ on $L^2(R)$, where $f$ is a real-valued…

Spectral Theory · Mathematics 2008-09-04 I. Gallagher , Th. Gallay , F. Nier

We improve the constant $\frac{\pi}{2}$ in $L^1$-Poincar\'e inequality on Hamming cube. For Gaussian space the sharp constant in $L^1$ inequality is known, and it is $\sqrt{\frac{\pi}{2}}$. For Hamming cube the sharp constant is not known,…

Probability · Mathematics 2019-06-04 Paata Ivanisvili , Dong Li , Ramon van Handel , Alexander Volberg

The psi function $\psi(x)$ is defined by $\psi(x)=\frac{\Gamma'(x)}{\Gamma(x)}$ and $\psi^{(i)}(x)$ for $i\in\mathbb{N}$ denote polygamma functions, where $\Gamma(x)$ is the gamma function. In this paper, we prove that the function $$…

Classical Analysis and ODEs · Mathematics 2015-05-12 Feng Qi

This paper is inspired by the work of J. S\'{a}ndor in 2006. In the paper, the authors establish some double inequalities involving the ratio $ \frac{\Gamma_{q}(x+1)}{ \Gamma_{q} \left( x+\frac{1}{2}\right)}$, where $\Gamma_{q}(x)$ is the…

Classical Analysis and ODEs · Mathematics 2015-07-01 Kwara Nantomah , Edward Prempeh

In this article, we determine two point distortion theorem and sharp coefficient estimates for the families of close-to-convex harmonic mappings whose analytic part is a convex function of order $\alpha$. By making use of these results, we…

Complex Variables · Mathematics 2018-02-28 Anbareeswaran Sairam Kaliraj

We investigate improved forms of the Bohr inequality, using the quantity $S_r/\pi$, for analytic selfmaps in class $\mathcal{B}$ of $\mathbb{D}$, where $S_r$ is the area measure of $\mathbb{D}_r$. We then generalize the inequality for…

Complex Variables · Mathematics 2025-10-28 Molla Basir Ahamed , Partha Pratim Roy , Sujoy Majumder

We present explicit formulas for the following family of parametric binomial sums involving harmonic numbers for $p=0,1,2$ and $|t|\leq1$. $$ \sum_{k=1}^{\infty}\frac{H_{k-1}t^k}{k^p\binom{n+k}{k}}\quad \mbox{and}\quad…

Number Theory · Mathematics 2021-05-11 Necdet Batir