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Domain Wall Nonlinear Quantization 域壁非线性量化
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040083
M. G. Ivanov
{"title":"Domain Wall Nonlinear Quantization","authors":"M. G. Ivanov","doi":"10.1134/S0202289321040083","DOIUrl":"10.1134/S0202289321040083","url":null,"abstract":"<p>Nonlinear quantization of the domain wall (relativistic membrane of codimension 1) is considered. The membrane dust equation is considered as an analogue of the Hamilton–Jacobi equation, which allows us to construct its quantum analogue. The resulting equation has the form of a nonlinear Klein–Fock–Gordon equation. It can be interpreted as the mean field approximation for a quantum domain wall. Dispersion relations are obtained for small perturbations (in a linear approximation). The group speed of perturbations does not exceed the speed of light. For perturbations propagating along the domain wall, in addition to the massless mode (as in the classical case), a massive one appears. The result may be interesting in condensed matter theory and in membrane quantization in superstring and supergravity theories.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"309 - 314"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4566376","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
Exact Solutions of Four-Dimensional Metric (boldsymbol{f(R)}) Gravity Depending on Two Variables 四维度量的精确解(boldsymbol{f(R)})重力依赖于两个变量
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040125
M. Shubina
{"title":"Exact Solutions of Four-Dimensional Metric (boldsymbol{f(R)}) Gravity Depending on Two Variables","authors":"M. Shubina","doi":"10.1134/S0202289321040125","DOIUrl":"10.1134/S0202289321040125","url":null,"abstract":"<p>We consider the metric <span>(f(R))</span> gravity model for the four-dimensional metric tensor depending on two variables, time and one spacelike coordinate. We obtain exact analytical vacuum solutions for different forms of the function <span>(f(R))</span>, which are solutions of cosmological type. These solutions are expressed in terms of arbitrary functions, which, under certain conditions, can be chosen as new variables.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"396 - 400"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4566488","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
A Note on “Traversable Wormholes in Einstein–Dirac–Maxwell Theory” 关于“爱因斯坦-狄拉克-麦克斯韦理论中可穿越虫洞”的注解
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040034
S. V. Bolokhov, K. A. Bronnikov, S. Krasnikov, M. V. Skvortsova
{"title":"A Note on “Traversable Wormholes in Einstein–Dirac–Maxwell Theory”","authors":"S. V. Bolokhov,&nbsp;K. A. Bronnikov,&nbsp;S. Krasnikov,&nbsp;M. V. Skvortsova","doi":"10.1134/S0202289321040034","DOIUrl":"10.1134/S0202289321040034","url":null,"abstract":"<p>In their Letter [Phys. Rev. Lett. <b>126</b>, 101102 (2021); arXiv: 2010.07317], J.L. Blázquez-Salcedo, C. Knoll, and E. Radu have constructed a very interesting class of wormhole solutions in general relativity (GR), supported by a pair of classical charged spinor fields obeying the Dirac equation. The main new feature of these solutions is that such Dirac spinor fields can possess exotic properties, necessary for the existence of static wormhole configurations in GR. The present note contains a few remarks clarifying some points concerning this approach.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"401 - 402"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4566499","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: 15
Generalized Ghost Version of Pilgrim Dark Energy in Loop Quantum Gravity Motivated Cosmology 环量子引力驱动宇宙学中朝圣者暗能量的广义幽灵版本
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040095
Sayani Maity, Ujjal Debnath
{"title":"Generalized Ghost Version of Pilgrim Dark Energy in Loop Quantum Gravity Motivated Cosmology","authors":"Sayani Maity,&nbsp;Ujjal Debnath","doi":"10.1134/S0202289321040095","DOIUrl":"10.1134/S0202289321040095","url":null,"abstract":"<p>One of the most interesting proposals of dark energy model is Pilgrim Dark Energy (PDE). This model is based on the assumption that the rapid expansion of the Universe is due to a phantom-like repulsive force that is capable to prevent black hole formation. In this study, we explore this phenomenon in the framework of Loop Quantum Gravity motivated cosmology by taking the Generalized Ghost version of PDE. An interaction between the constructed DE model and cold dark matter has also been considered. We evaluate the cosmological parameters, such as the Hubble and deceleration parameters, the equation of state parameter <span>(omega_{G})</span>, the squared speed of sound and also cosmological planes <span>(omega_{G})</span>–<span>(omega^{prime}_{G})</span> (where <span>(omega^{prime}_{G})</span> is a derivative of <span>(omega_{G})</span> with respect to the scale factor <span>(a)</span>) and the statefinder parameters <span>(r)</span> and <span>(s)</span> on the basis of the Generalized Ghost version of PDE, the parameter <span>(u)</span> and the interaction parameter <span>(delta)</span>. The trajectories of these cosmological diagnostic parameters give evidence that our constructed model can explain the phantom regime as well as the quintessence regime in the late Universe. Also, from a stability analysis, we see that our model is classically stable.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"375 - 382"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4567676","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
Cosmological Evolution of a Statistical System of Degenerate Scalarly Charged Fermions with an Asymmetric Scalar Doublet. I. Two-Component System of Assorted Charges 具有非对称标量双重态的简并标量带电费米子统计系统的宇宙学演化。一、组合收费双组分制
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S020228932104006X
Yu. G. Ignat’ev, A. A. Agathonov, D. Yu. Ignatyev
{"title":"Cosmological Evolution of a Statistical System of Degenerate Scalarly Charged Fermions with an Asymmetric Scalar Doublet. I. Two-Component System of Assorted Charges","authors":"Yu. G. Ignat’ev,&nbsp;A. A. Agathonov,&nbsp;D. Yu. Ignatyev","doi":"10.1134/S020228932104006X","DOIUrl":"10.1134/S020228932104006X","url":null,"abstract":"<p>Based on the mathematical model of a statistical system with scalar interaction of fermions, formulated earlier, a cosmological model based on a two-component statistical system of scalarly charged degenerate fermions interacting with an asymmetric scalar doublet of canonical and phantom scalar fields, is investigated. The asymptotic and limiting properties of the cosmological model are investigated, and it is shown that amon g all models there is a class of those with finite lifetime. The asymptotic behavior of the models near the corresponding singularities is investigated, and numerical implementations of such models are constructed.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"338 - 349"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568086","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: 2
Spherically Symmetric Space-Times in Generalized Hybrid Metric-Palatini Gravity 广义混合度量-帕拉蒂尼引力中的球对称时空
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040046
K. A. Bronnikov, S. V. Bolokhov, M. V. Skvortsova
{"title":"Spherically Symmetric Space-Times in Generalized Hybrid Metric-Palatini Gravity","authors":"K. A. Bronnikov,&nbsp;S. V. Bolokhov,&nbsp;M. V. Skvortsova","doi":"10.1134/S0202289321040046","DOIUrl":"10.1134/S0202289321040046","url":null,"abstract":"<p>We discuss vacuum static, spherically symmetric asymptotically flat solutions of the generalized hybrid metric-Palatini theory of gravity (generalized HMPG) suggested by Böhmer and Tamanini, involving both a metric <span>(g_{munu})</span> and an independent connection <span>(hat{Gamma}_{munu}^{alpha})</span>; the gravitational field Lagrangian is an arbitrary function <span>(f(R,P))</span> of two Ricci scalars, <span>(R)</span> obtained from <span>(g_{munu})</span> and <span>(P)</span> obtained from <span>({hat{Gamma}}_{munu}^{alpha})</span>. The theory admits a scalar-tensor representation with two scalars <span>(phi)</span> and <span>(xi)</span> and a potential <span>(V(phi,xi))</span> whose form depends on <span>(f(R,P))</span>. Solutions are obtained in the Einstein frame and transferred back to the original Jordan frame for a proper interpretation. In the completely studied case <span>(Vequiv 0)</span>, generic solutions contain naked singularities or describe traversable wormholes, and only some special cases represent black holes with extremal horizons. For <span>(V(phi,xi)neq 0)</span>, some examples of analytical solutions are obtained and shown to possess naked singularities. Even in the cases where the Einstein-frame metric <span>(g^{E}_{munu})</span> is found analytically, the scalar field equations need a numerical study, and if <span>(g^{E}_{munu})</span> contains a horizon, in the Jordan frame it turns to a singularity due to the corresponding conformal factor.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"358 - 374"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568088","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: 2
Dark Matter and Dark Radiation from Evaporating Kerr Primordial Black Holes 来自蒸发克尔原始黑洞的暗物质和暗辐射
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040101
Isabella Masina
{"title":"Dark Matter and Dark Radiation from Evaporating Kerr Primordial Black Holes","authors":"Isabella Masina","doi":"10.1134/S0202289321040101","DOIUrl":"10.1134/S0202289321040101","url":null,"abstract":"<p>The mechanism of generation of dark matter and dark radiation from the evaporation of primordial black holes is very interesting. We consider the case of Kerr black holes to generalize previous results obtained in the Schwarzschild case. For dark matter, the results do not change dramatically, and the bounds on warm dark matter apply similarly: in particular, the Kerr case cannot save the scenario of black hole domination for light dark matter. For dark radiation, the expectations for <span>(Delta N_{textrm{eff}})</span> do not change significantly with respect to the Schwarzschild case, but for an enhancement in the case of spin 2 particles: in the massless case, however, the projected experimental sensitivity would be reached only for extremal black holes.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"315 - 330"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568268","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: 27
Phase Flows in the Complete Model of Cosmological Evolution of the Asymmetric Scalar Higgs Doublet* 不对称标量希格斯双重态宇宙演化完整模型中的相流
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040071
Yu. G. Ignat’ev, I. A. Kokh
{"title":"Phase Flows in the Complete Model of Cosmological Evolution of the Asymmetric Scalar Higgs Doublet*","authors":"Yu. G. Ignat’ev,&nbsp;I. A. Kokh","doi":"10.1134/S0202289321040071","DOIUrl":"10.1134/S0202289321040071","url":null,"abstract":"<p>The flows of phase trajectories in cosmological models based on the asymmetric scalar Higgs doublet are investigated. It is shown that phase flows tend to split into several diverging flows. In this case, initially close phase trajectories can diverge significantly over time, which indicates the instability of the model with respect to finite perturbations.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"350 - 357"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568087","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
Friedmann Cosmology in Elliptic Functions 椭圆函数中的弗里德曼宇宙论
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040113
A. E. Pavlov
{"title":"Friedmann Cosmology in Elliptic Functions","authors":"A. E. Pavlov","doi":"10.1134/S0202289321040113","DOIUrl":"10.1134/S0202289321040113","url":null,"abstract":"<p>We present exact solutions to the Friedmann equation in standard <span>(Lambda)</span>CDM cosmology in Weierstrass and Jacobi functions. The right-hand side of the Friedmann equation, describing various contributions of matter sources, is considered in a generic form. It is proved that the problem of integration of the Friedmann equation for simple equations of state of a medium is reduced to solving Abel integrals for algebraic functions.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"403 - 408"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4564207","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
Precision Measurement of Gravitational Frequency Shift of Radio Signals Using Rao-Cramer Estimates 利用Rao-Cramer估计精确测量无线电信号的重力频移
IF 0.9 4区 物理与天体物理
Gravitation and Cosmology Pub Date : 2021-12-14 DOI: 10.1134/S0202289321040022
A. V. Belonenko, A. V. Gusev, V. N. Rudenko
{"title":"Precision Measurement of Gravitational Frequency Shift of Radio Signals Using Rao-Cramer Estimates","authors":"A. V. Belonenko,&nbsp;A. V. Gusev,&nbsp;V. N. Rudenko","doi":"10.1134/S0202289321040022","DOIUrl":"10.1134/S0202289321040022","url":null,"abstract":"<p>A method has been developed for precision measurement of the gravitational frequency shift of communication radio signals between a spacecraft and a ground tracking station, based on the maximum likelihood principle, using the Rao-Cramer limit estimates for the kinematic parameters associated with orbital motion. Numerical illustrations of the efficiency of the method are presented using the example of data obtained in experiments with the Spektr-R satellite as part of the VLBI system in the Radioastron mission. A compensatory “on-line” technique for suppressing Doppler and atmospheric noise has been implemented due to the presence of two modes of communication in gravity sessions: unidirectional (1w) and looped (2w). Recipes for reducing the magnitude of systematic errors are discussed.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":"27 4","pages":"383 - 391"},"PeriodicalIF":0.9,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4566486","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
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