博客李淼

1、徐一鸿的疯狂想法

玻尔说过，你的想法也许挺疯狂，但还没有疯狂到正确的地步。

爱因斯坦说，物理越简单越好，但不能更简单。

徐一鸿说，解决宇宙学常数谜题的想法越疯狂越好，但不能更疯狂。

他们在最近的文章

Relaxing the cosmological constant in the extreme ultra-infrared

提出了一个疯狂想法，认为引力在宇宙尺度上破坏了Lorentz对称，从而时间在大尺度上变得与空间不对称了。这样，宇宙学常数在某种意义上变成一个irrelevant operator，这样就自然变小了。

值得注意的是，A. Zee等人的想法引入了时间上的非局域性，他们引用Arkani-Hamed等人的文章说，要解决宇宙学常数问题，时间在大尺度上破坏了因果律。这篇文章是

Non-Local Modification of Gravity and the Cosmological Constant Problem

不用说，我非常同情这种观点，因为全息暗能量就破坏了因果律。我们最近对Casimir能量的计算，似乎也暗示因果律在大尺度上被破坏了。我们将继续沿着这条线走下去。关于 Casimir能量与全息原理的关系，我觉得有很深的东西可以挖，我们正考虑去挖。

2、全息暗能量的空间曲率和相互作用的研究

接着宣传一下我们自己的工作。最近，李霄栋、王爽、王一、张鑫和在下写了一篇文章

Probing interaction and spatial curvature in the holographic dark energy model

我引用一下这篇文章的摘要：

In this paper we place observational constraints on the interaction and spatial curvature in the holographic dark energy model. We consider three kinds of phenomenological interactions between holographic dark energy and matter, i.e., the interaction term $Q$ is proportional to the energy densities of dark energy ($\rho_{\Lambda}$), matter ($\rho_{m}$), and matter plus dark energy ($\rho_m+\rho_{\Lambda}$). For probing the interaction and spatial curvature in the holographic dark energy model, we use the latest observational data including the type Ia supernovae (SNIa) Constitution data, the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). Our results show that the interaction and spatial curvature in the holographic dark energy model are both rather small. Besides, it is interesting to find that there exists significant degeneracy between the phenomenological interaction and the spatial curvature in the holographic dark energy model.

3、Michael Green成为卢卡西教授

霍金今年67岁了，按照传统，他该从剑桥大学卢卡西教授的位置上退下来。我过去听谣言说霍金本人希望Andy Strominger接替他，看来Andy不愿意离开哈佛，接替他的是另一位研究弦论的教授Michael Green。

《String theorist takes over from Hawking》开头说：

String theorist Michael Green has been announced as the next Lucasian Professor of Mathematics at Cambridge University. Green, 63, will succeed Stephen Hawking who held the chair from 1980 before retiring last month at the age of 67 and taking up a distinguished research chair at the Perimeter Institute for Theoretical Physics in Canada.

这篇文章发表于 2009年10月23日, 星期五 16:49:15，属于分类 理论物理, 宇宙学。 你可以查看 HTML打印版 或通过 新闻聚合(RSS) 来追踪这篇文章的最新评论。