题　目：The Geometric Structure of Space-time 主讲人：许文郁教授(清华大学统计所) 时　间：100年4月22日(星期五)上午10:40-11:30 (上午10:20-10:40茶会於交大统计所429室举行) 地　点：交大综合一馆427室 Abstract In the late 1990s, observations of Type Ia supernovae led to the astounding discovery that the universe is expanding at an accelerating rate. The explanation of this anomalous acceleration has been one of the great challenges in physics since that discovery. In this talk, I will present cosmological models [1,2,3] that explain the cosmic acceleration via the geometric structure of space-time, without invoking mysterious, unseen “dark energy”. In this geometric structure of space-time, the roles of time, space and mass are related in new kind of relativity. There are four distinguishing features of these models: 1) the speed of light and the gravitational “ constant” are not constant, but vary with the evolution of the universe, 2) time has no beginning and no end; i.e., there is neither a big bang nor a big crunch singularity, 3) the spatial section of the universe is a 3-sphere, ruling out the possibility of a flat or hyperboloid geometry, and 4) the universe experiences phases of both acceleration and deceleration. One of these models is selected and tested against current cosmological observations of Type Ia supernovae, and is found to fit the redshift-luminosity distance data quite well. 敬 请 公 布 欢 迎 参 加 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.113.114.213