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Quanti.ati.n of Hori.on Area of Kerr–Newman–de Si.ter Black Hole

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Chi.ese Physi.s Letters 2019年第3期36卷 19-23页

作者： Y.Kenedy meitei T.i.ungochouba Si.gh i.ablu meitei Department of Mathemati.s Manipur University Department of Physi.s Modern College

Usi.g the adi.bati. i.vari.nt acti.n and applyi.g the Bohr–Sommerfeld quanti.ati.n rule and fi.st law of black hole thermodynami.s, a study of the quanti.ati.n of the entropy and hori.on area of a Kerr–Newman–de Si.ter black hole i. carri.d out. The same entropy spectrum i. obtai.ed i. two di.ferent coordi.ate systems. i. i. also observed that the spaci.g of the entropy spectrum i. i.dependent of the black hole parameters. Also, the correspondi.g quantum of hori.on area i. i. agreement wi.h the results of Bekenstei..

关键词： Quanti.ati.n Hori.on Si.ter Black Hole Newman

The Evoluti.n QSOs—The Opti.al Lumi.osi.y Functi.n

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i.ternati.nal Journal of Astronomy and Astrophysi.s 2013年第2期3卷 87-92页

作者： i.om ablu meitei K. Yugi.dro Si.gh Department of Physi.s Manipur University Canchipur India Department of Physi.s Pettigrew College Ukhrul India

Usi.g the data of the 2 Degree Fi.ld (2dF) QSO Redshi.t Survey (2QZ) and the associ.ted 6 Degree Fi.ld (6dF) QSO Redshi.t Survey (6QZ) of the Anglo-Australi.n Telescope, a study of the Opti.al Lumi.osi.y Functi.n of Quasi.Stellar Objects (QSOs) has been made to understand the evoluti.nary scenari. of QSOs. Di.ferent models for the QSO evoluti.n are studi.d. The two-power law model of the opti.al lumi.osi.y functi.n wi.h second order polynomi.l evoluti.n i. found to fi. best the observed QSO opti.al lumi.osi.y functi.n. We have also determi.ed an i.proved evoluti.nary model whi.h fi.s better than the second order polynomi.l evoluti.n model. The best fi. parameters for the observed opti.al lumi.osi.y functi.n have been determi.ed usi.g the Levenberg-Marquardt algori.hm of non-li.ear least square fi. for a flat uni.erse i.e., ΩΛ + Ωm = 1 and Ho = 70 km·s–1·Mpc–1. The observed slope of the log N - m curve i.e., 1.10 ± 0.01 reveals that there were more QSOs at larger di.tances (or look back ti.es) than there are locally whi.h, i. turn, i.di.ates that the QSOs are evolvi.g. The observed value of V/Vmax> i. found to be greater than 0.5 for di.ferent values of the cosmologi.al constant whi.h also hi.ts strong evoluti.n of the QSOs.

关键词： Galaxi.s Acti.e

Moti.n of a Test Parti.le i. the Kerr-Newman De/Anti.De Si.ter Space-Ti.e

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i.ternati.nal Journal of Astronomy and Astrophysi.s 2014年第2期4卷 365-373页

作者： Shanji. Hei.nam i.om ablu meitei Kangujam Yugi.dro Si.gh Department of Physi.s Manipur University Canchipur Imphal India Department of Physi.s Pettigrew College Ukhrul India

i. thi. paper we obtai. the geodesi. equati.ns of moti.n of a test parti.le (charged parti.le and photon) i. the Kerr-Newman de/anti.de Si.ter black hole by usi.g the Hami.ton-Jacobi.equati.n. We determi.e the posi.i.ns of the i.ner, outer and cosmologi.al hori.ons of the black hole. i. terms of the effecti.e potenti.ls, the trajectory of the test parti.le wi.hi. the i.ner hori.on i. studi.d. i. appears that there are stable ci.cular orbi.s of a charged parti.le and photon wi.hi. the i.ner hori.on and that the combi.ed effect of the charge and rotati.n of the Kerr-Newman de/anti.de Si.ter black hole and the coupli.g between the charge of the test parti.le and the electromagneti. fi.ld of the black hole may account for thi..

关键词： Geodesi. Equati.ns Kerr-Newman De/Anti De Si.ter Black Hole i.ner and Outer Event Hori.ons Stable Ci.cular Orbi.s

Doi.g Astronomy wi.h Small Telescopes

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i.ternati.nal Journal of Astronomy and Astrophysi.s 2014年第4期4卷 560-570页

作者： Kangujam Yugi.dro Si.gh i.om ablu meitei Salam Aji.kumar Si.gh Department of Physi.s Manipur University Canchipur Imphal India Department of Physi.s Pettigrew College Ukhrul India

We are playi.g a lead role for growth of astronomy and i.s quali.y teachi.g and research i. Mani.ur, a State located at northeast i.di. (longi.ude = 93°58'E;lati.ude = 24°44'N;alti.ude = 782 m). We have i.novati.ely desi.ned and constructed three cost effecti.e observatori.s, each costi.g a few hundred USD. These observatori.s are completely di.ferent i. desi.n and are perfectly usable for doi.g seri.us work on astronomi.al observati.n and measurements, usi.g small ground-based telescopes. One Celestron CGE1400 telescope i. housed wi.h equatori.l mounti.g i. one of three constructed observatori.s and the same observatory has been i.ducted, si.ce January 2012, as one of the members of the “Ori.n Project”, whi.h i. an i.ternati.nal project headquartered at Phoeni., Ari.ona, USA, dedi.ated for photometri. and spectroscopi. observati.ns of fi.e bri.ht vari.ble stars of the Ori.n constellati.n. We have been produci.g hi.h preci.i.n BVRi.photometri. data that match well wi.h those produced by other observatori.s enrolled i. the Ori.n project. Our photometri. data were presented and di.cussed i. the 33rd Annual Conference of the Soci.ty for Astronomi.al Sci.nces: Symposi.m on Telescope Sci.nce, held at Ontari., Cali.orni., USA duri.g June 12 - 14, 2014. Further, we could successfully demonstrate them to the enti.e populati.n of the State and play li.e shows of the observati.n of three spectacular astronomi.al events namely, solar ecli.se of 15th January 2010, lunar ecli.se of 10th December 2011 and Transi. of Venus of June 6, 2012. We have conducted a number of semi.ars and workshops for trai.i.g and research i. astronomy. i. the present paper, we would li.e descri.e our self-bui.t observatori.s, our observati.nal faci.i.i.s, the BVRi.photometri. data that we acqui.ed for the Ori.n project, and other acti.i.i.s undertaken for growth of astronomy acti.i.i.s i. the State of Mani.ur, i.di..

关键词： Self-Bui.t Observatori.s Ori.n Project Vari.ble Stars

Opti.al Lumi.osi.y Functi.n of the QSOs Observed wi.h the Sloan Di.i.al Sky Survey Data Release Seven (SDSS DR7)

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i.ternati.nal Journal of Astronomy and Astrophysi.s 2014年第3期4卷 474-478页

作者： Salam Aji.kumar Si.gh i.om ablu meitei Kangujam Yugi.dro Si.gh Department of Physi.s Manipur University Imphal India Department of Physi.s Pettigrew College Ukhrul India

We have determi.ed the Opti.al Lumi.osi.y Functi.n (OLF) of a sample of 80946 Quasi.Stellar Objects (QSOs) taken from the Sloan Di.i.al Sky Survey Data Release Seven (SDSS DR7) wi.h redshi.t range??0.3 z Mi.i.ue of numeri.al i.tegrati.n i. used. The sample of QSOs i. di.i.ed i.to seven sub-samples wi.h redshi.t i. the ranges: 0.30 z z z i.t i.terval i. bi.ned i. absolute magni.ude wi.h bi. wi.th ΔMi.= -0.5. A flat uni.erse wi.h cosmologi.al parameters Ωm = 0.3, Ω∧ = 0.7, and Hubble constant Ho = 70.0 km·s-1·Mpc-1 i. used. From the opti.al lumi.osi.y functi.n a clear evi.ence of AGN downsi.i.g i. observed, i.e. the number densi.y of the less lumi.ous AGNs peaks at lower redshi.t than the number densi.y of the more lumi.ous AGNs.

关键词： Quasi Stellar Objects (QSOs) Lumi.osi.y Functi.n