• 천문학회보
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• 제40권1호
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• pp.57.5-58
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• 2015

We describe relations between modern cosmology and general relativity in the historical context. We reveal some ironies imbedded in Einstein's final correction of his gravitational field equation in the context of cosmology in 1917 which has apparently opened a new era of modern physical cosmology. The ugly (according to Einstein) correction term was introduced only to build a static cosmology which turns out to be in flat contradiction with observation. Somehow, however, it is the correction term which has saved the modern cosmology from the genuine creativity of nature continuously revealed by astronomical observations. Whether the present precision cosmology is also a correct one is often ignored by the practitioners but still a pressing open question left for future theoretical and observational pursuits.

• 천문학회지
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• 제45권3호
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• pp.65-69
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• 2012

Physical cosmology tries to understand the Universe at large with its origin and evolution. Observational and experimental situations in cosmology do not allow us to proceed purely based on the empirical means. We examine in which sense our cosmological assumptions in fact have shaped our current cosmological worldview with consequent inevitable limits. Cosmology, as other branches of science and knowledge, is a construct of human imagination reflecting the popular belief system of the era. The question at issue deserves further philosophic discussions. In Whitehead's words, "philosophy, in one of its functions, is the critic of cosmologies". (Whitehead 1925).

• 건축역사연구
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• 제17권1호
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• pp.65-84
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• 2008

It is generally known that the temple structure in Korea was formalized by the ceremonial principle based on the Buddhist cosmology. But, there have been no concrete studies on how far the two have relationship with each other and what significance it implies in it. In other words, even though the temple structure reflects the Sumeru Mount cosmology which is the Buddhist cosmology, there is still uncertain aspects in the relationship between them. This research is a more concrete approach on what kind of corelation the Sumeru Mount cosmology has with the Korean temple structure. For this, the levels of related documents on the Buddhist cosmology and the Sumeru Mount cosmology have been arranged first. Then, on this basis, it is searched with what symbolism the cosmology has been accepted in the temple structure. The temple is a sacred space that holds Buddha and a profane space which the sattva (ordinary people) can approach at the same time. The site of the temple is also a land that is connected to the residence of sattva and a blissful area of prayer that they can be born again through Buddha at the same time. Thus, the double characteristics of sanctity and profanity are finally inter-connected with each other in the view point of Jinsokburi(Truth and Worldliness are not different), and the temple structure reflects this significance through the symbolism very well. Therefore, the correct recognition on the temple structure can be said as an important aspect to understand the purpose of Buddhism.

• 천문학논총
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• 제7권1호
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• pp.1-7
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• 1992

We may consider the following three fundamental epistemological questions concerning cosmology. Can cosmology at last understand the origin of the universe? Can computers at last create? Can life be formed at last synthetically? These questions are in some sense related to the liar paradox containing the self-reference and, therefore. may not be answered by recursive processes in finite time. There are, however. various implications such that the chaos may break the trap of the self-reference paradox. In other words, Goedel's incompleteness theorem would not apply to chaos, even if the chaos can be generated by recursive processes. Internal relations among cosmology, epistemology and chaos must be investigated in greater detail.

• 천문학논총
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• 제30권2호
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• pp.327-330
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• 2015

Cosmology considers the Hubble redshift of galaxy light by the Doppler effect as proof the Universe has been expanding since the Big Bang. However, cosmic dust that permeates the Universe also redshifts galaxy light that if not corrected over-predicts the velocities of all astronomical measurements inferred by the Doppler effect. Hubble redshifts corrected for cosmic dust suggest the Universe may not be expanding, the consequence of which may allow the outstanding problems in cosmology to possibly be resolved by Newtonian mechanics.

• Korean Journal of Mathematics
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• 제23권3호
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• pp.479-489
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• 2015

We study the GMGHS spacetime to analyze anisotropic cosmology model which represents homogeneous but anisotropically expanding(contracting)cosmology. In this paper we investigate the solution of GMGHS spacetime in form of doubly warped products possessing warping functions and find the Ricci curvature associated with three phases in the evolution of the universe.

• 천문학논총
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• 제30권2호
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• pp.309-313
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• 2015

If the present universe is slightly open then pre-inflation curvature would appear as a cosmic dark-flow component of the CMB dipole moment. We summarize current cosmological constraints on this cosmic dark flow and analyze the possible constraints on parameters characterizing the pre-inflating universe in an inflation model with a present-day very slightly open ${\Lambda}CDM$ cosmology. We employ an analytic model to show that for a broad class of inflation-generating effective potentials, the simple requirement that the observed dipole moment represents the pre-inflation curvature as it enters the horizon allows one to set upper and lower limits on the magnitude and wavelength scale of pre-inflation fluctuations in the inflaton field and the curvature parameter of the pre-inflation universe, as a function of the fraction of the total initial energy density in the inflaton field. We estimate that if the current CMB dipole is a universal dark flow (or if it is near the upper limit set by the Planck Collaboration) then the present constraints on ${\Lambda}CDM$ cosmological parameters imply rather small curvature ${\Omega}_k{\sim}0.1$ for the pre-inflating universe for a broad range of the fraction of the total energy in the inflaton field at the onset of inflation. Such small pre-inflation curvature might be indicative of open-inflation models in which there are two epochs of inflation.

• 한국철학논집
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• 제42호
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• pp.165-195
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• 2014

이 글의 목표는 양웅(揚雄)과 갈홍(葛洪)의 '현(玄)' 개념을 우주구조에 관한 이론을 중심으로 살펴보는 것이다. 고대 중국의 우주구조론은 '천(天)'에 대한 이해로부터 출발하여, 천체의 구조, 천지의 구조 및 위치관계 등의 문제를 통해 한대(漢代)에 그 이론이 체계적으로 정립되었다. 다만 중국 전통시기의 우주구조에 관한 논의는 대부분 천문(天文)과 역법(曆法)을 통해 발전했듯이, 인간의 관점에서 인간사를 해명하기 위해 전개되었다. 양웅과 갈홍 또한 이러한 맥락에서 각자의 우주구조론 체계를 정립하는데, 그 특징은 다음과 같다. 첫째, 양웅은 우주구조론가운데 개천설(蓋天說)을 비판하며 혼천설(渾天說)을 수용하여 발전시켰고, 갈홍은 혼천설을 지지하는 가운데 선야설(宣夜說)의 일부 논의를 수용하였다. 둘째, 양웅과 갈홍의 우주구조론은 그들의 우주생성론의 이론적 출발점이다. 천체의 구조와 천지의 위치관계를 다루는 우주구조론을 중심으로, 그들은 각자 우주만물 생성의 근원과 생성과정에 대한 논의를 전개한다. 이 과정에서 두 학자 모두 '현(玄)' 개념을 중심축으로 하여 우주론 체계를 건립하였다. 셋째, 양웅과 갈홍의 우주구조론은 그들 철학체계를 지탱하는 이론적 전제가 된다. 양웅은 우주구조에 관한 논의를 통해 천도(天道)와 인사(人事)의 관계를 모색하고, 갈홍은 우주구조론을 활용하여 신선도교 이론체계를 정립한다. 이처럼 양웅과 갈홍의 우주구조론은 우주생성론과 함께 우주론체계의 중요 구성 요소가 되며, 두 학자 모두 '현' 개념 중심의 우주구조론과 우주생성론을 바탕으로 각자의 철학체계를 정립하였다.

• 천문학논총
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• 제5권1호
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• pp.17-25
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• 1990

Rapid progress in modern computer industries now enables us to solve the Einstein equations numerically. In the first part of this paper we briefly review how to deal with those equations in relativistic astrophysics and cosmology. In the second part we introduce two examples-the Centrella and Wilson's cosmology and the Shapiro and Teukolsky's relativistic stellar cluster.

• 천문학회지
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• 제29권spc1호
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• pp.11-14
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• 1996

Super-inflation driven by dilaton/moduli kinetic energy is naturally realized in compactified string theory. Discussed are selected topics of recent development in string inflationary cosmology: kinematics of super-inflation, graceful exit triggered by quantum back-reaction, and classical and quantum power spectra of density and metric perturbations.