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5 questions
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Einstein Frame from String Frame
Consider the following low-energy effective action in $D$ dimensions for the bosonic sector:
$$
I=\frac{1}{2\kappa_0^2}\int d^Dx\sqrt{-g}e^{-{2\Phi}}\left[R-2\Lambda+4g_{\mu\nu}\partial^\mu\Phi\...
0
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1
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100
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Has Carl Brans got the wrong Brans-Dicke parameter ($w=1$) for String Theory?
In his 2005 paper The roots of scalar-tensor theory: an approximate history Carl H.Brans claims his Brans-Dicke Theory whose field equations can be derived from the following action
accords with ...
- 6,073
1
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1
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161
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Sign Wrong in Effective Action of Bosonic String?
In David Tong's Lectures in String Theory Chapter 7 he sketches a derivation of the low-energy effective action of the bosonic string $(7.16)$:
$$S=\frac{1}{2k_0^2}\int d^{26}X\sqrt{-G}e^{-2\Phi}\Big(\...
- 6,073
2
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1
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187
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Low energy effective action of bosonic string different in GSW and Polchinski/Tong?
In Superstring Theory vol.1 by Green, Schwarz and Witten (GSW) the low energy effective action of the bosonic string is given by:
$$S=-\frac{1}{2k_0^2}\int d^{26}x\sqrt{-g}e^{-2\Phi}({\cal R}-4\...
- 6,073
1
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1
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111
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Sign of effective action of bosonic string?
I've been looking at David Tong's Lectures on String Theory.
He states that the low-energy effective action of the bosonic string is given by
$$S=\frac{1}{2k_0^2}\int d^{26}X\sqrt{-G}e^{-2\Phi}\Big(\...
- 6,073