African Review of Physics最新文献

{"title":"FIVE DIMENSIONAL SPHERICAL SYMMETRIC UNIVERSE IN CREATION FIELD COSMOLOGY","authors":"U. K. Panigrahi, R. Patra, M. Sharma","doi":"10.9790/4861-06511418","DOIUrl":"https://doi.org/10.9790/4861-06511418","url":null,"abstract":"The phenomenon of expanding universe, primordial nucleon-synthesis and the observed isotropy of cosmic microwave background radiation (CMBR) are the three very important observations in astronomy. These were successfully explained by big-bang cosmology based on Einstein’s field equations. Smoot et al. [2] revealed that the earlier prediction of the FriedmanRobertson-Walker type of models do not always exactly match with our expectations. Some puzzling results regarding the red shifts from the extra galactic objects continue to contradict the theoretical explanations given by the big-bang type model. Also, CMBR discovery did not prove it to be outcome of a big-bang theory. In fact, Narlikar et al. [3] have proved the possibility of non-relic interpretation of CMBR. To explain such phenomenon, many alternative theories have been proposed from time to time. Hoyle [4], Bondi and Gold [5] proposed steady state theory in which the universe does neither have singular beginning nor an end on the cosmic time scale. To overcome this difficulty Hoyle and Narlikar [6] adopted a field theoretic approach by introducing a mass-less and charge-less scalar field C in the Einstein-Hilbert action to account for the matter creation. In the Cfield theory introduced by Hoyle and Narlikar, there is no big-bang type of singularity as in the steady state theory of Bondi and Gold [5]. A solution of Einstein’s field equations admitting radiation with negative energy mass less scalar creation field C was obtained by Narlikar and Padmanabhan [1]. The study of Hoyle and Narlikar theory [6-8] of space-times with higher dimensions ____________________ mitasharma08@gmail.com was carried out by Chaterjee and Banarjee [9]. RajBali and Tikekar [10] studied C field Cosmology with variable G in the flat FriedmanRobertson-Walker model and with non flat FRW space time by Raj Bali and Kumawat [11]. The solutions of Einstien’s field equations in the presence of creation field have been obtained for different Binachi type universes by Singh and Chaubey [12]. In the present work, we have studied the Hoyle and Narlikar C-field cosmology in spherical symmetric space time. We have assumed that , = , that is, the creation field C is a function of time‘t’ only.","PeriodicalId":7403,"journal":{"name":"African Review of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87946386","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}

{"title":"Expansion of Rindler Coordinate Theory and Light’s Doppler Effect","authors":"Sangwha Yi","doi":"10.2139/ssrn.3508038","DOIUrl":"https://doi.org/10.2139/ssrn.3508038","url":null,"abstract":"In the general theory of relativity the Rindler coordinate theory has been extended to the Rindler coordinate theory of accelerated observer that has already some initial velocity. In this paper, we present this extended theory that uses the tetrad as the new method, and discover the new inverse-coordinate transformation. Specially, if, a0 < 0 , this theory treats the observer with the initial velocity that does slowdown by the constant negative acceleration in the Rindler’s time-space. We consider the light’s Doppler Effect in the accelerated system as well as the decelerated system.","PeriodicalId":7403,"journal":{"name":"African Review of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76450075","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}

{"title":"Quantum Field Theory with Electric-Magnetic Duality and Spin-Mass Duality but Without Grand Unication and Supersymmetry","authors":"Rainer W. Kuhne","doi":"10.20944/PREPRINTS201806.0383.V1","DOIUrl":"https://doi.org/10.20944/PREPRINTS201806.0383.V1","url":null,"abstract":"Abstract: I present a generalization of quantum electrodynamics which includes Diracmagnetic monop oles and the Salam magnetic photon. This quantum electromagnetodynamics has many attractive features. (1) It explains the quantization of electric charge. (2) It describes symmetrized Maxwell equations. (3) It is manifestly covariant. (4) It describes local four-potentials. (5) It avoids the unphysicalDirac string. (6) It predicts a second kind of electromagnetic radiation which can be veried by a tabletop experiment. An eect of this radiation may have been observed by August Kundt in 1885. Furthermore I discuss a generalization of General Relativity which includes Cartan's torsion. I discuss the mathematical denition, concrete description, and physical meaning of Cartan's torsion. I argue that the electric-magnetic duality of quantum electromagnetodynamics is analogous to the spin-mass duality of Einstein-Cartan theory. A quantum version of this theory requires that the torsion tensor corresponds to a spin-3 boson called tordion which is shown to have a rest mass close to the Planck mass. Moreover I present an empirically satised fundamental equation of unied eld theory which includes the fundamental constants of electromagnetism and gravity. I conclude with the remark that the concepts presented here require neither Grand Unication nor supersymmetry.","PeriodicalId":7403,"journal":{"name":"African Review of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73853023","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}

{"title":"STACKING FAULTS IN THE SINGLE CRYSTALS","authors":"Mihir M. Vora, A. Vora","doi":"10.15407/spqeo12.04.421","DOIUrl":"https://doi.org/10.15407/spqeo12.04.421","url":null,"abstract":"0 ≤ ≤ x have been grown by a direct vapour transport techn ique (DVT) in the laboratory. The structural characterizations of these crystals are made by XRD method. The particle size for a nu mber of reflections has been calculated using the Scherrer’s formula. A con siderable variation is shown in the deformation ( α ) and growth ( β ) fault probabilities in In xMoSe 2 ( ) 1 0 ≤ ≤ x single crystal due to off-stoichiometry, which pos sesses the stacking fault in the single crystal.","PeriodicalId":7403,"journal":{"name":"African Review of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74755570","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}