t**********m
发帖数: 205 | 1 既然大爆炸理论得到了梵蒂冈的认可，那么我们来分析一下：创造生命的大爆炸理论究
竟是什么东西？
上一篇博客我谈到了广义相对论是什么东西，参见
http://www.galaxyanatomy.com/
'General Relativity is very simple. It is equivalent to one sentence:
There exists one and only one local inertial reference frame at any point of
a spacetime manifold.
This is similar to the situation that
There exists one and only one local tangent plane at any point of a surface.'
上述一句话就是著名的爱因斯坦的引力等效原理。等效原理讲的就是：引力跟其它三种
相互作用力有本质的不同，引力可以通过参考标架的变换来消灭掉！
爱因斯坦是对的。我们的身体每天遭受着引力的相互作用，而且逆来顺受，已经习惯了
。如果你要... 阅读全帖 |
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G****n
发帖数: 145 | 2 But Andrei Shleifer, who won the clark medal is the real deal!
The law and economics of self-dealing[PDF] from uva.nl…, R La Porta, F
Lopez-de-Silanes, A Shleifer - 2005 - nber.org
... Andrei Shleifer Department of Economics Harvard University Littauer
Center M-9 Cambridge,
MA 02138 and NBER a*******[email protected] Page 3. 1 1. Introduction. Over the
last twenty
years, both academic and practical approaches to corporate ...
Cited by 462 - Related articles - Library Search - BL Direct - All 71
vers... 阅读全帖 |
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f*******d
发帖数: 339 | 3 I think you meant Copernicus principle. Also, such reasoning
for introducing comoving coordinate is unnecessary and incorrect.
Even if we do not use comoving coordinate, the expansion of
Universe does not violate Copernicus principle: all these galaxies end
up in infinite far away (if the Universe is forever expanding)!
Indeed, according to general relativity, we could describe the space time
in any well-posed coordinate system. Introducing comoving coordinates
is merely a convinience.
The disti |
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G****n
发帖数: 145 | 4 长江各领域教授论文引用次数
Between trust and control: Developing confidence in partner cooperation in
alliances
[PDF] from cuny.edu…, BS Teng - Academy of management Review, 1998 - JSTOR
Strategic alliances have been recognized as arenas with potential for
opportunistic behavior
by partners. Hence, a firm needs to have an adequate level of confidence in
its partner's
cooperative behavior. In this article we examine the notion of confidence in
partner ...
Cited by 1749 - Related articles - BL Direct - All 9 v... 阅读全帖 |
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G****n
发帖数: 145 | 5 He H 100 + papers
Convergence from discrete-to continuous-time contingent claims prices[PDF]
from yale.eduH He - Review of Financial Studies, 1990 - Soc Financial
Studies
Convergence of Contingent Claims Prices stocks and one bond available for
trading, markets
cannot be com- pleted by dynamic trading, and options cannot be priced by
arbitrage. This is
not the case in the continuous-time model, in which markets can be completed
by ...
Cited by 174 - Related articles - Library Search - All 13 ver... 阅读全帖 |
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G****n
发帖数: 145 | 6 Between trust and control: Developing confidence in partner cooperation in
alliances
[PDF] from cuny.edu…, BS Teng - Academy of management Review, 1998 - JSTOR
Strategic alliances have been recognized as arenas with potential for
opportunistic behavior
by partners. Hence, a firm needs to have an adequate level of confidence in
its partner's
cooperative behavior. In this article we examine the notion of confidence in
partner ...
Cited by 1749 - Related articles - BL Direct - All 9 versions
A reso... 阅读全帖 |
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p*****k
发帖数: 318 | 7 jason04, since v_T=1+1*S_T/L_T as you indicated,
your last equation is simply:
L_T = 2+T = S_T = (v_T-1)*L_T
hence v_T = 2 = 1+ln((T+2)/2)
creepingdog, try searching "comoving frame" |
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x********9
发帖数: 31 | 8 VaR is typically used to compute the capital reserve. Generally, you need
capital when your asset and liability do not perfectly comove. The amount of
capital you need depends on the VaR level of your portfolio. You may want
to use capital to absorb sudden unpredicted loss in a relatively short
horizon. THat's how VaR is used in practice. |
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l**n
发帖数: 67 | 9 Cosmological redshift(Hubble redshift)
Now let go back to cosmology and for the time being forget about
the gravitational redshift since it's small anyway. In principle
the cosmological redshift can be described similarly, but we
must stress that the cosmological redshift(z) is deeply rooted
in the fact that we live in a (accelarating?) expanding,(curved?),
universe. In order to describe this z, we need to have a model
of universe. It's mathmatical description is model dependent!
comoving coordi |
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l**n
发帖数: 67 | 10
end
time
coordinates
Thank you very much for your comment. I guess we all agree that
whatever
physics should be independent of the coordinates we are using. It's
just
a matter of convinience to use specific coordinate in specific
questions.
I think(guess) the reason why comoving coordinate is used here is
because
the universe is expanding. It's perfectly valid to use euclidean frame
also
but with more trouble in maths. To me a euclidean frame should be used
to describe the static universe in wh |
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c**********g
发帖数: 222 | 11
CMBR.
the
???
distance.
equivalent
I also think that you are wrong here. let's consider the photon's
equation.
c^2 dt^2=a^2 dr^2/(1-kr^2). here, k=-1,0,1. then c dt=a dr/Sqrt[1-k
r^2];
So, we know the meaning of c*(t_now-t_then). it is the PHYSICAL
distance that
the photon travel. But it is not either angular diameter distance,
comoving distance or luminosity distance. The reason is due to the a
or the
expansion of the universe. Because the universe is expanding, this d
i |
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