In this paper, when a given curve on the total manifold of a Riemannian submersion is transferred to the base manifold, the character of the corresponding curve is examined. First, the case of a Frenet curve on the total manifold being a Frenet curve on the base manifold along a Riemannian submersion is investigated. Then, the condition that a circle on the total manifold (respectively a helix) is a circle (respectively, a helix) or a geodesic on the base manifold along a Riemannian submersion is obtained. We also investigate the curvatures of the original curve on the total manifold and the corresponding curve on the base manifold in terms of Riemannian submersions.
{"title":"Certain curves along Riemannian submersions","authors":"Gözde Özkan Tükel, B. Şahin, Tunahan Turhan","doi":"10.2298/fil2303905o","DOIUrl":"https://doi.org/10.2298/fil2303905o","url":null,"abstract":"In this paper, when a given curve on the total manifold of a Riemannian submersion is transferred to the base manifold, the character of the corresponding curve is examined. First, the case of a Frenet curve on the total manifold being a Frenet curve on the base manifold along a Riemannian submersion is investigated. Then, the condition that a circle on the total manifold (respectively a helix) is a circle (respectively, a helix) or a geodesic on the base manifold along a Riemannian submersion is obtained. We also investigate the curvatures of the original curve on the total manifold and the corresponding curve on the base manifold in terms of Riemannian submersions.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"107 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68268016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the Neumann problem with Leray-Lions type operator. Using the classical variational theory, we prove the existence, uniqueness and multiplicity of solutions. As far as we know, this is the first attempt to investigate such a fourth-order problem involving Leray-Lions type operators.
{"title":"On a fourth-order Neumann problem in variable exponent spaces","authors":"J. Zuo, A. El, S. Taarabti, Dušan D. Repovš","doi":"10.2298/fil2307027z","DOIUrl":"https://doi.org/10.2298/fil2307027z","url":null,"abstract":"We study the Neumann problem with Leray-Lions type operator. Using the classical variational theory, we prove the existence, uniqueness and multiplicity of solutions. As far as we know, this is the first attempt to investigate such a fourth-order problem involving Leray-Lions type operators.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we derive the asymptotic expressions of the scaled value function and the optimal redemption boundary of stock loan with dividend-paying near maturity. Using the equation satisfied by the derivative of the value function at the exercise boundary, we set up the asymptotic expression for the boundary. When the risk-free rate r is smaller than the loan rate ?, i.e., r < ?, the boundary tends to Ke?T0 in parabolic-logarithm form, this case is the main result. For the case r ? ?, the corresponding problem returns back to a usual American call option with interest-free rate r ? ? and the existing results can be utilized to make proper adjustments for the stock loan. The matched expansion for the value function is performed with a small parameter. Numerical examples are provided to demonstrate the effectiveness of the proposed method.
{"title":"Asymptotic analysis for stock loans near maturity","authors":"Yongqing Xu","doi":"10.2298/fil2307105x","DOIUrl":"https://doi.org/10.2298/fil2307105x","url":null,"abstract":"In this paper, we derive the asymptotic expressions of the scaled value function and the optimal redemption boundary of stock loan with dividend-paying near maturity. Using the equation satisfied by the derivative of the value function at the exercise boundary, we set up the asymptotic expression for the boundary. When the risk-free rate r is smaller than the loan rate ?, i.e., r < ?, the boundary tends to Ke?T0 in parabolic-logarithm form, this case is the main result. For the case r ? ?, the corresponding problem returns back to a usual American call option with interest-free rate r ? ? and the existing results can be utilized to make proper adjustments for the stock loan. The matched expansion for the value function is performed with a small parameter. Numerical examples are provided to demonstrate the effectiveness of the proposed method.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"94 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paperwe investigate the spectrum and the Drazin spectrum and their pseudo spectral analogues, for linear relations between Banach spaces and corresponding spectra, the generalized Drazinmeromorphic pseudospectrum. More specifically, the generalized Drazin-meromorphic pseudospectrum for a linear relations on a Banach space is studied. We also make several observations about the level set of the generalized Drazin-meromorphic pseudospectrum of linear relations. Furthermore, it is shown that pseudospectrum has no isolated points, has a finite number of connected components and each component contains an element from the generalized Drazin-meromorphic spectrum.
{"title":"Generalized Drazin-meromorphic pseudospectrum for multivalued linear relation","authors":"K. Mahfoudhi, B. Saadaoui, V. Rakočević","doi":"10.2298/fil2301193m","DOIUrl":"https://doi.org/10.2298/fil2301193m","url":null,"abstract":"In this paperwe investigate the spectrum and the Drazin spectrum and their pseudo spectral analogues, for linear relations between Banach spaces and corresponding spectra, the generalized Drazinmeromorphic pseudospectrum. More specifically, the generalized Drazin-meromorphic pseudospectrum for a linear relations on a Banach space is studied. We also make several observations about the level set of the generalized Drazin-meromorphic pseudospectrum of linear relations. Furthermore, it is shown that pseudospectrum has no isolated points, has a finite number of connected components and each component contains an element from the generalized Drazin-meromorphic spectrum.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68266689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper develops the notion of relative demicompact elements of an algebra with respect to a Banach subalgebra as a generalization of relative demicompact linear operators acting on Banach spaces. Drawing on this novel notion, we build a new class of Fredholm perturbation regarding a given Banach subalgebra B which contains its inessential ideal kB and the set of left Fredholm perturbations suggested in [6]. The developed class of Fredholm perturbation exhibits that is a two-sided closed ideal of B that is key in the characterization of the weyl spectrum of elements affiliated with B.
{"title":"Stability of relative essential spectra involving relative demicompactness concept in Banach subalgebra","authors":"Slim Chelly","doi":"10.2298/fil2303891c","DOIUrl":"https://doi.org/10.2298/fil2303891c","url":null,"abstract":"This paper develops the notion of relative demicompact elements of an algebra with respect to a Banach subalgebra as a generalization of relative demicompact linear operators acting on Banach spaces. Drawing on this novel notion, we build a new class of Fredholm perturbation regarding a given Banach subalgebra B which contains its inessential ideal kB and the set of left Fredholm perturbations suggested in [6]. The developed class of Fredholm perturbation exhibits that is a two-sided closed ideal of B that is key in the characterization of the weyl spectrum of elements affiliated with B.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68267953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we introduce and study the S-pseudospectra of linear operators defined by nonstrict inequality in a Hilbert space. Inspired by A. B?ttcher?s result [3], we prove that the S-resolvent norm of bounded linear operators is not constant in any open set of the S-resolvent set. Beside, we find a characterization of the S-pseudospectrum of bounded linear operator by means the S-spectra of all perturbed operators with perturbations that have norms strictly less than ?.
{"title":"A characterization of S-pseudospectra of linear operators in a Hilbert space","authors":"A. Ammar, Ameni Bouchekoua, A. Jeribi","doi":"10.2298/fil2305331a","DOIUrl":"https://doi.org/10.2298/fil2305331a","url":null,"abstract":"In this work, we introduce and study the S-pseudospectra of linear operators defined by nonstrict inequality in a Hilbert space. Inspired by A. B?ttcher?s result [3], we prove that the S-resolvent norm of bounded linear operators is not constant in any open set of the S-resolvent set. Beside, we find a characterization of the S-pseudospectrum of bounded linear operator by means the S-spectra of all perturbed operators with perturbations that have norms strictly less than ?.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"16 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68269449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A number of properties for the classes Bp-1 and B*p have been proved. The class Bp-1 characterizes the Lp- inequality involving the averaging operator and the class B*p characterizes the Lp-inequality involving the adjoint averaging operator. The reverse inequalities involving the integral operators in Lp? have also been studied.
{"title":"Integral operators on grand Lebesgue spaces and related weights with properties","authors":"Santosh Kaushik, T. Khan, H. Chaudhary","doi":"10.2298/fil2306767k","DOIUrl":"https://doi.org/10.2298/fil2306767k","url":null,"abstract":"A number of properties for the classes Bp-1 and B*p have been proved. The class Bp-1 characterizes the Lp- inequality involving the averaging operator and the class B*p characterizes the Lp-inequality involving the adjoint averaging operator. The reverse inequalities involving the integral operators in Lp? have also been studied.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68270880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Ameziane Hassani, A. Blali, A. El amrani, Beldi El
The goal of this work is to introduce the two-parameter conformable fractional semigroups and provide a definition of its infinitesimal generator. For such generators, we develop multiple results. In addition, we show that the two-parameter conformable fractional semigroups provide a solution for two-parameter conformable fractional abstract Cauchy problems.
{"title":"Two-parameter conformable fractional semigroups and abstract Cauchy problems","authors":"R. Ameziane Hassani, A. Blali, A. El amrani, Beldi El","doi":"10.2298/fil2308303a","DOIUrl":"https://doi.org/10.2298/fil2308303a","url":null,"abstract":"The goal of this work is to introduce the two-parameter conformable fractional semigroups and provide a definition of its infinitesimal generator. For such generators, we develop multiple results. In addition, we show that the two-parameter conformable fractional semigroups provide a solution for two-parameter conformable fractional abstract Cauchy problems.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68272890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Hilbert space, the finite-dimensional exact controllability of an abstract semilinear fractional composite relaxation equation is researched. We make assumptions about the parameters in the equation and suppose that the linear equation associated with the abstract semilinear fractional relaxation equation is approximately controllable. We apply the variational method, the resolvent theory and the fixed point trick to demonstrate the finite-dimensional exact controllability of the abstract semilinear equation. An application is given in the last paper to testify our results.
{"title":"Finite-dimensional exact controllability of an abstract semilinear fractional composite relaxation equation","authors":"Yixing Liang, Z. Fan, Gang Li","doi":"10.2298/fil2308347l","DOIUrl":"https://doi.org/10.2298/fil2308347l","url":null,"abstract":"In Hilbert space, the finite-dimensional exact controllability of an abstract semilinear fractional composite relaxation equation is researched. We make assumptions about the parameters in the equation and suppose that the linear equation associated with the abstract semilinear fractional relaxation equation is approximately controllable. We apply the variational method, the resolvent theory and the fixed point trick to demonstrate the finite-dimensional exact controllability of the abstract semilinear equation. An application is given in the last paper to testify our results.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68273048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper studies the exponential stability result is derived for the second-order fractional stochastic integro-differential equations (FSIDEs) driven by sub-fractional Brownian motion (sub-fBm). By constructing a successive approximation method, we present pth moment exponential stability result of second-order FSIDEs using stochastic analysis techniques and fractional calculus (FC). At last, an example is demonstrated to illustrate the obtained theoretical result.
{"title":"Exponential stability of second-order fractional stochastic integro-differential equations","authors":"K. Dhanalakshmi, P. Balasubramaniam","doi":"10.2298/fil2309699d","DOIUrl":"https://doi.org/10.2298/fil2309699d","url":null,"abstract":"In this paper studies the exponential stability result is derived for the second-order fractional stochastic integro-differential equations (FSIDEs) driven by sub-fractional Brownian motion (sub-fBm). By constructing a successive approximation method, we present pth moment exponential stability result of second-order FSIDEs using stochastic analysis techniques and fractional calculus (FC). At last, an example is demonstrated to illustrate the obtained theoretical result.","PeriodicalId":12305,"journal":{"name":"Filomat","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135595644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}