首页 > 最新文献

Modern Physics Letters A最新文献

英文 中文
Accelerating universe in terms of Hankel function index 以汉克尔函数指数表示的加速宇宙
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2024-01-06 DOI: 10.1142/s021773232350178x
K. Suratgar, M. Mohsenzadeh, E. Yusofi, F. Taghizadeh-Farahmand
In this paper, [Formula: see text] cosmology is proposed for the accelerating universe with asymptotic de Sitter expansion in terms of Hankel function index [Formula: see text]. To some extent, both the initial expansion during early inflation and the current accelerated expansion can be studied with a vacuum cosmic fluid, i.e. [Formula: see text] in the pure de Sitter phase. Observational data further support the notion of a quasi-vacuum fluid, rather than a pure vacuum, contributing to the quasi-de Sitter acceleration in both the early and late universe. By examining the asymptotic expansion of the Henkel function as an approximate solution of the Mukhanov–Sasaki equation, we seek a more detailed study of quasi-de Sitter solutions in cosmology containing vacuum-like fluid.
本文从汉克尔函数指数[公式:见正文]的角度提出了渐近德西特膨胀的加速宇宙学[公式:见正文]。在某种程度上,早期膨胀时的初始膨胀和当前的加速膨胀都可以用真空宇宙流体来研究,即[公式:见正文]纯德西特阶段。观测数据进一步支持了准真空流体而非纯真空的概念,准真空流体对早期和晚期宇宙的准德西特加速都有贡献。通过研究作为穆哈诺夫-萨基方程近似解的亨克尔函数的渐近展开,我们寻求对宇宙学中包含类真空流体的准德西特解进行更详细的研究。
{"title":"Accelerating universe in terms of Hankel function index","authors":"K. Suratgar, M. Mohsenzadeh, E. Yusofi, F. Taghizadeh-Farahmand","doi":"10.1142/s021773232350178x","DOIUrl":"https://doi.org/10.1142/s021773232350178x","url":null,"abstract":"In this paper, [Formula: see text] cosmology is proposed for the accelerating universe with asymptotic de Sitter expansion in terms of Hankel function index [Formula: see text]. To some extent, both the initial expansion during early inflation and the current accelerated expansion can be studied with a vacuum cosmic fluid, i.e. [Formula: see text] in the pure de Sitter phase. Observational data further support the notion of a quasi-vacuum fluid, rather than a pure vacuum, contributing to the quasi-de Sitter acceleration in both the early and late universe. By examining the asymptotic expansion of the Henkel function as an approximate solution of the Mukhanov–Sasaki equation, we seek a more detailed study of quasi-de Sitter solutions in cosmology containing vacuum-like fluid.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"53 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139449295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Numerical investigations of the fractional order derivative-based accelerating universe in the modified gravity 修正引力中基于分数阶导数的加速宇宙数值研究
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2024-01-06 DOI: 10.1142/s0217732323501808
A. Alderremy, J. Gómez-Aguilar, Z. Sabir, Muhammad Asif Zahoor Raja, Shaban Aly
In this work, a Liouville–Caputo fractional order (FO) derivative for the mathematical system based on the accelerating universe in the modified gravity (AUMG), i.e. FO-AUMG is proposed to get more accurate solutions. The nonlinear dynamics of the FO-AUMG is classified into five dynamics. The performances of the designed nonlinear FO-AUMG are numerically stimulated with the stochastic procedures of Levenberg–Marquardt backpropagated (LMB) scheme-based neural networks. The statics for FO-AUMS is used for the nonlinear FO-AUMG as 72%, 16% and 12% for training, authorization, and testing. Twenty neurons in hidden layers have been used to approximate the solution of the nonlinear FO-AUMS. The comparison of three different cases of the nonlinear FO-AUMS is performed with dataset generated by Adams method. To validate the uniformity, legitimacy, precision, and competence of LMB-based adaptive neural networks, the outcomes of the state transitions parameters, regression, correlation, error-histogram plots have been exploited.
本研究提出了基于修正重力加速宇宙(AUMG)数学系统的 Liouville-Caputo 分数阶(FO)导数,即 FO-AUMG,以获得更精确的解。FO-AUMG 的非线性动力学分为五个动力学。利用基于 Levenberg-Marquardt 反向传播(LMB)方案的神经网络随机程序对所设计的非线性 FO-AUMG 的性能进行了数值激励。在非线性 FO-AUMG 的训练、授权和测试中,FO-AUMS 的统计量分别为 72%、16% 和 12%。隐藏层中的 20 个神经元被用来近似非线性 FO-AUMS 的解决方案。利用亚当斯方法生成的数据集对非线性 FO-AUMS 的三种不同情况进行了比较。为了验证基于 LMB 的自适应神经网络的统一性、合理性、精确性和能力,我们利用了状态转换参数、回归、相关性、误差-柱状图等结果。
{"title":"Numerical investigations of the fractional order derivative-based accelerating universe in the modified gravity","authors":"A. Alderremy, J. Gómez-Aguilar, Z. Sabir, Muhammad Asif Zahoor Raja, Shaban Aly","doi":"10.1142/s0217732323501808","DOIUrl":"https://doi.org/10.1142/s0217732323501808","url":null,"abstract":"In this work, a Liouville–Caputo fractional order (FO) derivative for the mathematical system based on the accelerating universe in the modified gravity (AUMG), i.e. FO-AUMG is proposed to get more accurate solutions. The nonlinear dynamics of the FO-AUMG is classified into five dynamics. The performances of the designed nonlinear FO-AUMG are numerically stimulated with the stochastic procedures of Levenberg–Marquardt backpropagated (LMB) scheme-based neural networks. The statics for FO-AUMS is used for the nonlinear FO-AUMG as 72%, 16% and 12% for training, authorization, and testing. Twenty neurons in hidden layers have been used to approximate the solution of the nonlinear FO-AUMS. The comparison of three different cases of the nonlinear FO-AUMS is performed with dataset generated by Adams method. To validate the uniformity, legitimacy, precision, and competence of LMB-based adaptive neural networks, the outcomes of the state transitions parameters, regression, correlation, error-histogram plots have been exploited.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"61 43","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139449263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Multipartite quantum key agreement against d-dimensional collective-dephasing noise 对抗 d 维集体相干噪声的多方量子密钥协议
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-30 DOI: 10.1142/s0217732323501791
Wan-Li Hong, Chen-Ming Bai, Su-juan Zhang, Lu Liu
In this paper, we introduce a novel model for collective-dephasing noise in [Formula: see text]-dimensional space. After that, we construct a multi-particle entangled state to resist the given collective-dephasing noise. Based on the measurement laws of multi-particle entangled state under two different bases, we propose a multipartite quantum key agreement protocol. In this protocol, multiple participants would obtain [Formula: see text]-dimensional secret key even if the quantum channel is influenced by collective-dephasing noise. The security analysis indicates that this protocol can resist both dishonest participant attack and the outsider attacks which include intercept-resend attack and entangle-measure attack. By comparing with the existing QKA protocols, it is clear that our protocol has greater universality from the perspective of dimensionality and number of participants.
本文介绍了[公式:见正文]维空间中集体相干噪声的新模型。然后,我们构建了一个多粒子纠缠态来抵抗给定的集体-相干噪声。根据多粒子纠缠态在两种不同基础下的测量规律,我们提出了一种多方量子密钥协议。在该协议中,即使量子信道受到集体相消噪声的影响,多个参与者也能获得[公式:见正文]维密匙。安全性分析表明,该协议既能抵御不诚实参与者的攻击,也能抵御外部攻击,包括拦截-发送攻击和纠缠-测量攻击。与现有的 QKA 协议相比,从维度和参与人数的角度来看,我们的协议显然具有更大的通用性。
{"title":"Multipartite quantum key agreement against d-dimensional collective-dephasing noise","authors":"Wan-Li Hong, Chen-Ming Bai, Su-juan Zhang, Lu Liu","doi":"10.1142/s0217732323501791","DOIUrl":"https://doi.org/10.1142/s0217732323501791","url":null,"abstract":"In this paper, we introduce a novel model for collective-dephasing noise in [Formula: see text]-dimensional space. After that, we construct a multi-particle entangled state to resist the given collective-dephasing noise. Based on the measurement laws of multi-particle entangled state under two different bases, we propose a multipartite quantum key agreement protocol. In this protocol, multiple participants would obtain [Formula: see text]-dimensional secret key even if the quantum channel is influenced by collective-dephasing noise. The security analysis indicates that this protocol can resist both dishonest participant attack and the outsider attacks which include intercept-resend attack and entangle-measure attack. By comparing with the existing QKA protocols, it is clear that our protocol has greater universality from the perspective of dimensionality and number of participants.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":" 5","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139137509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Connection between gravitational and inertial masses of compound objects and the weak equivalence principle 复合物体的引力质量和惯性质量与弱等效原理之间的联系
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-22 DOI: 10.1142/s0217732323501778
A. Silenko
The connection between gravitational and inertial masses of compound objects (e.g. nucleons, nuclei, atoms, and molecules) in the presence of rapid internal motions of their constituent parts is considered. The equality of gravitational and inertial masses of such objects confirming the weak equivalence principle is proven provided that their moving constituent parts are confined. The result is very nontrivial because of a substantial difference between particle dynamics in noninertial frames and gravitational fields. Paradoxically, gravitational effects are different for the same particles moving in the closed box and in the free space. The gravitational and inertial masses are equal to the corresponding kinematic masses. In contrast, gravitational masses of ensembles of noninteracting moving particles cannot be introduced because the total gravitational forces acting on these ensembles do not correspond to their kinematic masses.
研究考虑了复合物体(如核子、原子核、原子和分子)在其构成部分快速内部运动时的引力质量和惯性质量之间的联系。只要其运动的构成部分是封闭的,就能证明这些物体的引力质量和惯性质量相等,证实了弱等效原理。由于非惯性框架中的粒子动力学与引力场中的粒子动力学之间存在很大差异,因此结果非常不简单。矛盾的是,同样的粒子在封闭箱中运动和在自由空间中运动,引力效应是不同的。引力质量和惯性质量等于相应的运动质量。相反,不能引入非相互作用运动粒子集合体的引力质量,因为作用在这些集合体上的总引力与其运动质量不一致。
{"title":"Connection between gravitational and inertial masses of compound objects and the weak equivalence principle","authors":"A. Silenko","doi":"10.1142/s0217732323501778","DOIUrl":"https://doi.org/10.1142/s0217732323501778","url":null,"abstract":"The connection between gravitational and inertial masses of compound objects (e.g. nucleons, nuclei, atoms, and molecules) in the presence of rapid internal motions of their constituent parts is considered. The equality of gravitational and inertial masses of such objects confirming the weak equivalence principle is proven provided that their moving constituent parts are confined. The result is very nontrivial because of a substantial difference between particle dynamics in noninertial frames and gravitational fields. Paradoxically, gravitational effects are different for the same particles moving in the closed box and in the free space. The gravitational and inertial masses are equal to the corresponding kinematic masses. In contrast, gravitational masses of ensembles of noninteracting moving particles cannot be introduced because the total gravitational forces acting on these ensembles do not correspond to their kinematic masses.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"12 7","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Energy model in Bianchi type-V spacetime via RIF integration techniques 通过 RIF 积分技术建立比安奇 V 型时空中的能量模型
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-18 DOI: 10.1142/s021773232350164x
Shair-a-Yazdan, Muhammad Jawed Iqbal, Mark Hickman
This paper investigates the Noether versus Killing symmetries and their associated conservation laws of Bianchi type-V spacetimes. The study is carried out using the Maple RIFSIMP package, which converts a set of nonlinear differential equations into the reduced involutive form (RIF). This technique generates an RIF tree, where each branch is solved to obtain the explicit forms of Noether symmetries. Separate RIF trees are used to represent each group. We derive a general expression for the Noether symmetry connected to homothety, and then we investigate this Noether symmetry in each separate group. To explore whether dark energy is associated with Bianchi type-V spacetime, we examine the energy density of each spacetime obtained in association with the Ricci scalar. The symmetries of the larger groups, 11- and 17-dimensional, are presented separately in the tables.
本文研究了比安奇 V 型时空的诺特对称与基林对称及其相关守恒定律。研究使用 Maple RIFSIMP 软件包进行,该软件包可将一组非线性微分方程转换为还原渐开线形式(RIF)。该技术生成了一棵 RIF 树,对每个分支进行求解,以获得诺特对称性的显式形式。每个组都使用单独的 RIF 树来表示。我们推导出与同神性相连的诺特对称性的一般表达式,然后研究每个独立组中的诺特对称性。为了探索暗能量是否与边奇型-V 时空相关,我们研究了与利玛窦标量相关的每个时空的能量密度。表中分别列出了11维和17维等较大组的对称性。
{"title":"Energy model in Bianchi type-V spacetime via RIF integration techniques","authors":"Shair-a-Yazdan, Muhammad Jawed Iqbal, Mark Hickman","doi":"10.1142/s021773232350164x","DOIUrl":"https://doi.org/10.1142/s021773232350164x","url":null,"abstract":"This paper investigates the Noether versus Killing symmetries and their associated conservation laws of Bianchi type-V spacetimes. The study is carried out using the Maple RIFSIMP package, which converts a set of nonlinear differential equations into the reduced involutive form (RIF). This technique generates an RIF tree, where each branch is solved to obtain the explicit forms of Noether symmetries. Separate RIF trees are used to represent each group. We derive a general expression for the Noether symmetry connected to homothety, and then we investigate this Noether symmetry in each separate group. To explore whether dark energy is associated with Bianchi type-V spacetime, we examine the energy density of each spacetime obtained in association with the Ricci scalar. The symmetries of the larger groups, 11- and 17-dimensional, are presented separately in the tables.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":" 35","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138964500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Chaplygin gas equation in curvature-matter coupling gravity 曲率-物质耦合引力中的查普利金气体方程
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-14 DOI: 10.1142/s0217732323501705
E. Baffou, P. H. R. S. Moraes, C. G. Assolohou, M. Houndjo
In this paper, we study the Chaplygin gas equation in curvature-matter coupling gravity to describe the observed expansion of the universe. We consider the Chaplygin gas equation of state in terms of the energy density [Formula: see text] and pressure [Formula: see text], by the relationship [Formula: see text] and the curvature-matter coupling gravity as [Formula: see text], where [Formula: see text] is a positive constant, [Formula: see text] and [Formula: see text] denote, respectively, the Ricci scalar and the trace of energy–momentum tensor. Considering the gravitational lagrangian in the form [Formula: see text], where we used two forms of [Formula: see text] and by assuming a perfect fluid as matter source, we determined through the modified Friedmann equations, the corresponding energy and pressure for each model. By using the free parameters of our models, we performed the numerical results of the energy conditions to study its viability. Furthermore, we have derived some cosmological parameters like deceleration parameter and statefinder parameters and graphically investigated the nature of these parameters in Chaplygin gas model.
本文研究了曲率-物质耦合引力中的查普利金气体方程,以描述观测到的宇宙膨胀。我们用能量密度[式:见正文]和压力[式:见正文]来考虑查普利金气体状态方程,关系式为[式:见正文],曲率-物质耦合引力为[式:见正文],其中[式:见正文]为正常数,[式:见正文]和[式:见正文]分别表示利玛窦标量和能动张量的迹。考虑到[式:见正文]形式的引力拉格朗日(我们使用了[式:见正文]的两种形式),并假设完全流体为物质源,我们通过修正的弗里德曼方程确定了每个模型相应的能量和压力。通过使用模型的自由参数,我们对能量条件进行了数值计算,以研究其可行性。此外,我们还推导出了一些宇宙学参数,如减速参数和寻态参数,并以图形方式研究了这些参数在查普利金气体模型中的性质。
{"title":"Chaplygin gas equation in curvature-matter coupling gravity","authors":"E. Baffou, P. H. R. S. Moraes, C. G. Assolohou, M. Houndjo","doi":"10.1142/s0217732323501705","DOIUrl":"https://doi.org/10.1142/s0217732323501705","url":null,"abstract":"In this paper, we study the Chaplygin gas equation in curvature-matter coupling gravity to describe the observed expansion of the universe. We consider the Chaplygin gas equation of state in terms of the energy density [Formula: see text] and pressure [Formula: see text], by the relationship [Formula: see text] and the curvature-matter coupling gravity as [Formula: see text], where [Formula: see text] is a positive constant, [Formula: see text] and [Formula: see text] denote, respectively, the Ricci scalar and the trace of energy–momentum tensor. Considering the gravitational lagrangian in the form [Formula: see text], where we used two forms of [Formula: see text] and by assuming a perfect fluid as matter source, we determined through the modified Friedmann equations, the corresponding energy and pressure for each model. By using the free parameters of our models, we performed the numerical results of the energy conditions to study its viability. Furthermore, we have derived some cosmological parameters like deceleration parameter and statefinder parameters and graphically investigated the nature of these parameters in Chaplygin gas model.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"46 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139001602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
T-violation and the dark sector T-violation 和暗部门
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-14 DOI: 10.1142/s0217732323501651
R. Vilela Mendes
It is argued, as a working hypothesis, that “normal” and dark matter interactions can only be [Formula: see text]- and [Formula: see text]-violating. One way to implement this idea is to consider that time reversal in dark matter is implemented, not by an antiunitary operator, but by an unitary operator. It is shown how this occurs naturally in the context of complex spacetime with an extended symmetry group.
作为一种工作假设,有人认为 "正常 "和暗物质的相互作用只能是[公式:见正文]-和[公式:见正文]-违反。实现这一观点的一种方法是考虑暗物质中的时间反转不是由反单元算子而是由单元算子实现的。这说明了在具有扩展对称群的复时空背景下,这种情况是如何自然发生的。
{"title":"T-violation and the dark sector","authors":"R. Vilela Mendes","doi":"10.1142/s0217732323501651","DOIUrl":"https://doi.org/10.1142/s0217732323501651","url":null,"abstract":"It is argued, as a working hypothesis, that “normal” and dark matter interactions can only be [Formula: see text]- and [Formula: see text]-violating. One way to implement this idea is to consider that time reversal in dark matter is implemented, not by an antiunitary operator, but by an unitary operator. It is shown how this occurs naturally in the context of complex spacetime with an extended symmetry group.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"6 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138975469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Conformally flat generalized Ricci recurrent spacetimes and curvature-squared gravity 共形平坦广义利玛窦循环时空与曲率平方引力
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-14 DOI: 10.1142/s0217732323501663
Dipankar Hazra, Uday Chand De
First, we illustrate that a conformally flat generalized Ricci recurrent spacetime is a perfect fluid spacetime. As a consequence, we prove that such a spacetime represents a dust matter fluid, stiff matter and dark energy era under certain restrictions on the Ricci scalar. Then we establish that such a spacetime is a Robertson–Walker spacetime. Also, we note that in a conformally flat generalized Ricci recurrent spacetime, the fluid is shear-free, vorticity-free and its flow vector is hypersurface orthogonal. We investigate a conformally flat generalized Ricci recurrent spacetime as a solution of curvature-squared gravity theory. In this study, various energy conditions in terms of the Ricci scalar are examined and state that the Universe is in an accelerating phase and satisfies the weak, null, dominant, and strong energy conditions.
首先,我们说明了保角平坦广义利玛窦循环时空是一个完美的流体时空。因此,我们证明,在对利玛窦标量的某些限制下,这样的时空代表了尘埃物质流体、僵硬物质和暗能量时代。然后,我们确定这样的时空是罗伯逊-沃克时空。此外,我们还注意到,在保角平坦广义利玛窦递归时空中,流体是无剪切、无涡旋的,而且其流动矢量是超曲面正交的。我们研究了作为曲率平方引力理论解的保角平坦广义利玛窦循环时空。在这项研究中,我们考察了利玛窦标量的各种能量条件,并指出宇宙处于加速阶段,满足弱能量条件、空能量条件、主导能量条件和强能量条件。
{"title":"Conformally flat generalized Ricci recurrent spacetimes and curvature-squared gravity","authors":"Dipankar Hazra, Uday Chand De","doi":"10.1142/s0217732323501663","DOIUrl":"https://doi.org/10.1142/s0217732323501663","url":null,"abstract":"First, we illustrate that a conformally flat generalized Ricci recurrent spacetime is a perfect fluid spacetime. As a consequence, we prove that such a spacetime represents a dust matter fluid, stiff matter and dark energy era under certain restrictions on the Ricci scalar. Then we establish that such a spacetime is a Robertson–Walker spacetime. Also, we note that in a conformally flat generalized Ricci recurrent spacetime, the fluid is shear-free, vorticity-free and its flow vector is hypersurface orthogonal. We investigate a conformally flat generalized Ricci recurrent spacetime as a solution of curvature-squared gravity theory. In this study, various energy conditions in terms of the Ricci scalar are examined and state that the Universe is in an accelerating phase and satisfies the weak, null, dominant, and strong energy conditions.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"388 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138974198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Analytical quasibound states of black holes emerging from modified theories of gravity 修正引力理论中出现的黑洞解析准结合态
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-11 DOI: 10.1142/s0217732323501602
David Senjaya
The Rayleigh–Schrodinger method or more commonly called time independent perturbation theory is a powerful method to solve a Hamiltonian system with a relatively small perturbation [W. Nolting, Theoretical Physics 7: Quantum Mechanics–Methods and Applications (Springer International, 2017); F. Schwabl, Quantum Mechanics, 4th edn. (Springer, 2007)]. In this work, we make use of the Rayleigh–Schrodinger method to formulate a general method to calculate quasibound states of static spherically symmetric black hole solutions arising from modified theories of gravity. We discover that the Schwarzschild-like term corresponds to the main Hamiltonian while the modified theory of gravity’s contribution of the spacetime metric corresponds to the perturbation terms. At the end, formula to calculate main Hamiltonian and perturbed Hamiltonian are discovered and presented.
雷利-薛定谔方法或通常所说的时间无关扰动理论是求解具有相对较小扰动的哈密顿系统的一种强有力的方法[W.Nolting, Theoretical Physics 7: Quantum Mechanics-Methods and Applications (Springer International, 2017); F. Schwabl, Quantum Mechanics, 4th edn. (Springer, 2007)]。(Springer, 2007)]。在这项工作中,我们利用瑞利-薛定谔方法,提出了一种计算修正引力理论产生的静态球对称黑洞解的准边界态的一般方法。我们发现,类似于施瓦兹希尔德的项对应于主哈密顿,而修正引力理论的时空度量贡献则对应于扰动项。最后,我们发现并提出了主哈密顿和扰动哈密顿的计算公式。
{"title":"Analytical quasibound states of black holes emerging from modified theories of gravity","authors":"David Senjaya","doi":"10.1142/s0217732323501602","DOIUrl":"https://doi.org/10.1142/s0217732323501602","url":null,"abstract":"The Rayleigh–Schrodinger method or more commonly called time independent perturbation theory is a powerful method to solve a Hamiltonian system with a relatively small perturbation [W. Nolting, Theoretical Physics 7: Quantum Mechanics–Methods and Applications (Springer International, 2017); F. Schwabl, Quantum Mechanics, 4th edn. (Springer, 2007)]. In this work, we make use of the Rayleigh–Schrodinger method to formulate a general method to calculate quasibound states of static spherically symmetric black hole solutions arising from modified theories of gravity. We discover that the Schwarzschild-like term corresponds to the main Hamiltonian while the modified theory of gravity’s contribution of the spacetime metric corresponds to the perturbation terms. At the end, formula to calculate main Hamiltonian and perturbed Hamiltonian are discovered and presented.","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"54 4","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139010413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Thermodynamic geometry of dyonic black holes in AdS in extended phase space 扩展相空间 AdS 中双子黑洞的热力学几何学
IF 1.4 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-11 DOI: 10.1142/s0217732323501730
Aditya Singh
Ruppeiner scalar curvature can be considered as an empirical tool to explore the nature of interaction among the microstructures of black holes. In the extended phase space, the phase transitions and criticality are investigated for the dyonic black holes in an ensemble, where the electric potential [Formula: see text] is fixed. At first, we described the thermodynamic properties of dyonic black holes to investigate the [Formula: see text] criticality. Further, the Ruppeiner scalar curvature is calculated in an ensemble with fixed [Formula: see text] utilizing the fluctuation coordinates [Formula: see text]. The behavior of interactions among the microstructures of the dyonic black holes in AdS is studied where the dominance of attractive or repulsive interaction is found to be dependent on the values of electric potential [Formula: see text].
鲁佩纳标量曲率可被视为探索黑洞微结构之间相互作用性质的经验工具。在扩展相空间中,我们研究了在电势[公式:见正文]固定的集合中的双子黑洞的相变和临界。首先,我们描述了双子黑洞的热力学性质,以研究[公式:见正文]临界性。此外,我们利用波动坐标[公式:见正文]计算了固定[公式:见正文]的集合中的鲁佩纳标量曲率。研究了 AdS 中双子黑洞微结构之间的相互作用行为,发现吸引力或排斥力相互作用的主导地位取决于电势值[公式:见正文]。
{"title":"Thermodynamic geometry of dyonic black holes in AdS in extended phase space","authors":"Aditya Singh","doi":"10.1142/s0217732323501730","DOIUrl":"https://doi.org/10.1142/s0217732323501730","url":null,"abstract":"Ruppeiner scalar curvature can be considered as an empirical tool to explore the nature of interaction among the microstructures of black holes. In the extended phase space, the phase transitions and criticality are investigated for the dyonic black holes in an ensemble, where the electric potential [Formula: see text] is fixed. At first, we described the thermodynamic properties of dyonic black holes to investigate the [Formula: see text] criticality. Further, the Ruppeiner scalar curvature is calculated in an ensemble with fixed [Formula: see text] utilizing the fluctuation coordinates [Formula: see text]. The behavior of interactions among the microstructures of the dyonic black holes in AdS is studied where the dominance of attractive or repulsive interaction is found to be dependent on the values of electric potential [Formula: see text].","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":"40 7","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139010435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Modern Physics Letters A
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1