CuboPub Date : 2023-08-28DOI: 10.56754/0719-0646.2502.289
A. Ghandouri, H. Mejjaoli, S. Omri
{"title":"On generalized Hardy spaces associated with singular partial differential operators","authors":"A. Ghandouri, H. Mejjaoli, S. Omri","doi":"10.56754/0719-0646.2502.289","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.289","url":null,"abstract":"We define and study the Hardy spaces associated with singular partial differential operators. Also, a characterization by mean of atomic decomposition is investigated.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46750227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-09DOI: 10.56754/0719-0646.2502.273
Mehdi Dehghanian, Choonkill Park, Y. Sayyari
{"title":"Stability of ternary antiderivation in ternary Banach algebras via fixed point theorem","authors":"Mehdi Dehghanian, Choonkill Park, Y. Sayyari","doi":"10.56754/0719-0646.2502.273","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.273","url":null,"abstract":"In this paper, we introduce the concept of ternary antiderivation on ternary Banach algebras and investigate the stability of ternary antiderivation in ternary Banach algebras, associated to the $(alpha,beta)$-functional inequality: begin{align*} &Vert mathcal{F}(x+y+z)-mathcal{F}(x+z)-mathcal{F}(y-x+z)-mathcal{F}(x-z)Vert nonumber &leq Vert alpha (mathcal{F}(x+y-z)+mathcal{F}(x-z)-mathcal{F}(y))Vert + Vert beta (mathcal{F}(x-z) &+mathcal{F}(x)-mathcal{F}(z))Vert end{align*} where $alpha$ and $beta$ are fixed nonzero complex numbers with $vertalpha vert +vert beta vert<2$ by using the fixed point method.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43820847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-07DOI: 10.56754/0719-0646.2502.251
P. Eloe, Jeffrey T. Neugebauer
{"title":"Maximum, anti-maximum principles and monotone methods for boundary value problems for Riemann-Liouville fractional differential equations in neighborhoods of simple eigenvalues","authors":"P. Eloe, Jeffrey T. Neugebauer","doi":"10.56754/0719-0646.2502.251","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.251","url":null,"abstract":"It has been shown that, under suitable hypotheses, boundary value problems of the form, $Ly+lambda y=f,$ $BC y =0$ where $L$ is a linear ordinary or partial differential operator and $BC$ denotes a linear boundary operator, then there exists $Lambda >0$ such that $fge 0$ implies $lambda y ge 0$ for $lambdain [-Lambda ,Lambda ]setminus{0},$ where $y$ is the unique solution of $Ly+lambda y=f,$ $BC y =0$. So, the boundary value problem satisfies a maximum principle for $lambdain [-Lambda ,0)$ and the boundary value problem satisfies an anti-maximum principle for $lambdain (0, Lambda ]$. In an abstract result, we shall provide suitable hypotheses such that boundary value problems of the form, $D_{0}^{alpha}y+beta D_{0}^{alpha -1}y=f,$ $BC y =0$ where $D_{0}^{alpha}$ is a Riemann-Liouville fractional differentiable operator of order $alpha$, $1<alpha le 2$, and $BC$ denotes a linear boundary operator, then there exists $mathcal{B} >0$ such that $fge 0$ implies $beta D_{0}^{alpha -1}y ge 0$ for $beta in [-mathcal{B} ,mathcal{B} ]setminus{0},$ where $y$ is the unique solution of $D_{0}^{alpha}y+beta D_{0}^{alpha -1}y =f,$ $BC y =0$. Two examples are provided in which the hypotheses of the abstract theorem are satisfied to obtain the sign property of $beta D_{0}^{alpha -1}y.$ The boundary conditions are chosen so that with further analysis a sign property of $beta y$ is also obtained. One application of monotone methods is developed to illustrate the utility of the abstract result.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43858847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-05DOI: 10.56754/0719-0646.2502.231
A. Bensalem, Abdelkrim Salim, B. Ahmad, M. Benchohra
{"title":"Existence and controllability of integrodifferential equations with non-instantaneous impulses in Fréchet spaces","authors":"A. Bensalem, Abdelkrim Salim, B. Ahmad, M. Benchohra","doi":"10.56754/0719-0646.2502.231","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.231","url":null,"abstract":"In this paper, we investigate existence of mild solutions to a non-instantaneous integrodifferential equation via resolvent operators in the sense of Grimmer in Fréchet spaces. Utilizing the technique of measures of noncompactness in conjunction with the Darbo's fixed point theorem, we present sufficient criteria ensuring the controllability of the given problem. An illustrative example is also discussed.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44889535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-04DOI: 10.56754/0719-0646.2502.211
Sahar M. A. Maqbol, R. S. Jain, B. Reddy
{"title":"On stability of nonlocal neutral stochastic integro differential equations with random impulses and Poisson jumps","authors":"Sahar M. A. Maqbol, R. S. Jain, B. Reddy","doi":"10.56754/0719-0646.2502.211","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.211","url":null,"abstract":"This article aims to examine the existence and Hyers-Ulam stability of non-local random impulsive neutral stochastic integrodifferential delayed equations with Poisson jumps. Initially, we prove the existence of mild solutions to the equations by using the Banach fixed point theorem. Then, we investigate stability via the continuous dependence of solutions on the initial value. Next, we study the Hyers-Ulam stability results under the Lipschitz condition on a bounded and closed interval. Finally, we give an illustrative example of our main result.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49215480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-01DOI: 10.56754/0719-0646.2502.331
E. Ballico
{"title":"Osculating varieties and their joins: $mathbb{P}^1times mathbb{P}^1$","authors":"E. Ballico","doi":"10.56754/0719-0646.2502.331","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.331","url":null,"abstract":"Let $Xsubset PP^r$ be an integral projective variety. We study the dimensions of the joins of several copies of the osculating varieties $J(X,m)$ of $X$. Our methods are general, but we give a full description in all cases only if $X$ is a linearly normal embedding of $PP^1times PP^1$. For these embeddings of $PP^1times PP^1$ we give several examples and then study the joins of one copy of $J(X,m)$ and an arbitrary number of copies of $X$.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41427504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-08-01DOI: 10.56754/0719-0646.2502.321
F. Soltani, Slim Ben Rejeb
{"title":"Laeng-Morpurgo-type uncertainty inequalities for the Weinstein transform","authors":"F. Soltani, Slim Ben Rejeb","doi":"10.56754/0719-0646.2502.321","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.321","url":null,"abstract":"In this work, by combining Carlson-type and Nash-type inequalities for the Weinstein transform $mathscr{F}_W$ on $mathbb{K}=mathbb{R}^{d-1}times[0,infty)$, we show Laeng-Morpurgo-type uncertainty inequalities. We establish also local-type uncertainty inequalities for the Weinstein transform $mathscr{F}_W$, and we deduce a Heisenberg-Pauli-Weyl-type inequality for this transform.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45178958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-07-19DOI: 10.56754/0719-0646.2502.195
S. Dragomir, S. S. Dragomir
{"title":"Several inequalities for an integral transform of positive operators in Hilbert spaces with applications","authors":"S. Dragomir, S. S. Dragomir","doi":"10.56754/0719-0646.2502.195","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.195","url":null,"abstract":"For a continuous and positive function (wleft( lambda right) ,) (lambda>0) and (mu ) a positive measure on ((0,infty )) we consider the following Integral Transform [ begin{equation*} mathcal{D}left( w,mu right) left( Tright) :=int_{0}^{infty }wleft(lambda right) left( lambda +Tright)^{-1}dmu left( lambda right) , end{equation*} ] where the integral is assumed to exist for (T) a postive operator on a complex Hilbert space (H). We show among others that, if ( beta geq A geq alpha > 0, , B > 0 ) with ( M geq B-A geq m > 0 ) for some constants ( alpha, beta, m, M ), then [ begin{align*} 0 & leq frac{m^{2}}{M^{2}}left[ mathcal{D}left( w,mu right) left(betaright) - mathcal{D}left( w,mu right) left(M+betaright) right] & leq frac{m^{2}}{M}left[ mathcal{D}left( w,mu right) left(betaright) - mathcal{D}left( w,mu right) left(M+betaright) right] left( B-Aright)^{-1} & leq mathcal{D}left( w,mu right) left(Aright) - mathcal{D}left(w,muright) left(Bright) & leq frac{M^{2}}{m}left[ mathcal{D}left( w,mu right) left(alpharight) - mathcal{D}left( w,mu right) left(m+alpharight) right] left(B-Aright)^{-1} & leq frac{M^{2}}{m^{2}}left[ mathcal{D}left( w,mu right) left(alpharight) - mathcal{D}left( w,mu right) left(m+alpharight) right]. end{align*} ] Some examples for operator monotone and operator convex functions as well as for integral transforms (mathcal{D}left( cdot ,cdot right) ) related to the exponential and logarithmic functions are also provided.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48523841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-07-19DOI: 10.56754/0719-0646.2502.173
A. Zerki, K. Bachouche, K. Ait-Mahiout
{"title":"Existence of solutions for higher order $phi-$Laplacian BVPs on the half-line using a one-sided Nagumo condition with nonordered upper and lower solutions","authors":"A. Zerki, K. Bachouche, K. Ait-Mahiout","doi":"10.56754/0719-0646.2502.173","DOIUrl":"https://doi.org/10.56754/0719-0646.2502.173","url":null,"abstract":"In this paper, we consider the following ((n+1))st order bvp on the half line with a (phi-)Laplacian operator [ begin{cases} (phi(u^{(n)}))'(t) = f(t,u(t),ldots,u^{(n)}(t)), & text{a.e.},, tin [0,+infty), n in mathbb{N}setminus{0}, u^{(i)}(0) = A_{i}, , i=0,ldots,n-2, u^{(n-1)}(0) + au^{(n)}(0) = B, u^{(n)}(+infty) = C. end{cases} ] The existence of solutions is obtained by applying Schaefer's fixed point theorem under a one-sided Nagumo condition with nonordered lower and upper solutions method where (f) is a (L^{1})-Carathéodory function.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44413330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CuboPub Date : 2023-04-20DOI: 10.56754/0719-0646.2501.057
Mudasir Younis, Nikola Mirkov, A. Savić, M. Pantović, S. Radenović
{"title":"Some critical remarks on recent results concerning $digamma-$contractions in $b$-metric spaces","authors":"Mudasir Younis, Nikola Mirkov, A. Savić, M. Pantović, S. Radenović","doi":"10.56754/0719-0646.2501.057","DOIUrl":"https://doi.org/10.56754/0719-0646.2501.057","url":null,"abstract":"This paper aims to correct recent results on a generalized class of $digamma-$contractions in the context of $b-$metric spaces. The significant work consists of repairing some novel results involving $digamma-$contraction within the structure of $b$-metric spaces. Our objective is to take advantage of the property $(F1)$ instead of the four properties viz. $(F1)$, $(F2)$, $(F3)$ and $(F4)$ applied in the results of Nazam textit{et al.} [``Coincidence and common fixed point theorems for four mappings satisfying $(alpha_s,F)-$contraction\", Nonlinear Anal: Model. Control., vol. 23, no. 5, pp. 664--690, 2018]. Our approach of proving the results utilizing only the condition $(F1)$ enriches, improves, and condenses the proofs of a multitude of results in the existing state-of-art.","PeriodicalId":36416,"journal":{"name":"Cubo","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}