報(bào)告主題：Energy-Momentum Conservation and Nonlocalizability of Gravitational Energy in GR
　　主講人：吳兆顏教授
　　地點(diǎn)：屏峰校區(qū)理學(xué)A樓報(bào)告廳
　　時(shí)間：2013年5月20日（周一）9:00-10:00
　　主辦單位：理學(xué)院
　　聯(lián)系電話(huà)：85290306

　　主講人簡(jiǎn)介：
　　吳兆顏，教授，吉林大學(xué)物理系理論物理專(zhuān)業(yè)畢業(yè)。1982-1984美國(guó)旺尼辦達(dá)大學(xué)物理系訪(fǎng)問(wèn)學(xué)者。 主要科研工作領(lǐng)域?yàn)榱孔咏^熱演化的幾何及量子中間統(tǒng)計(jì)理論。

　　講座摘要：
　　This talk is based on a general variational principle, and Noether's theorem is revisited. It is shown that the long existing pseudotensor problem of gravitational energy-momentum, is only a result of misreading Noether's theorem and mistaking different geometrical, physical objects as one and the same. As a matter of fact, all the Noether's conserved quantities in general relativity are scalars, their conservation currents are vector fields. The difficulty of non-localizability of gravitational energy-momentum, which is a direct consequence of the pseudotensor property, does not really exist. Each dynamic system (matter field plus metric field) has infinitely many so-called canonical energy-momentums, which are the conservation currents due to the coordinate shift invariance of its action, but it has only one energy-momentum of matter which appears in Einstein's field equation. It is pointed out the sum of energy-momentum 4-vector can not be defined in a curved spacetime. The law of energy conservation just holds approximately in a spacetime region which is approximately flat. Gravitational wave does not carry energy-momentum.