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Bob
  • Member for 8 years, 9 months
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9 votes
0 answers
314 views

Basic questions on the PPN formalism in General Relativity

8 votes
1 answer
348 views

Would dark matter (as a BEC) be captured by Black Holes, Neutron Stars, etc?

7 votes
1 answer
1k views

Units of Einstein-Hilbert Action

5 votes
2 answers
1k views

Why is a gauge transformation more than just a coordinate transformation?

5 votes
1 answer
532 views

How to find 4-velocity components in a perturbed metric?

4 votes
2 answers
630 views

Why are extra timelike dimensions seldom considered? [duplicate]

4 votes
1 answer
1k views

Equation of motion from Polyakov action

3 votes
1 answer
242 views

Is it possible to directly test whether or not the vacuum gravitates?

3 votes
1 answer
174 views

Equation of Motion for Polyakov Action with a mass term

3 votes
1 answer
199 views

Equation of state at the end of inflation

2 votes
0 answers
51 views

Equation of state of a universe full electrons

2 votes
0 answers
58 views

Help with understanding gauge transformation within PPN formalism

2 votes
1 answer
142 views

Is $(\Box \nabla_\nu-\nabla_\nu\Box)\phi=0$?

2 votes
0 answers
90 views

What would happen if very light particles (of large de Broglie wavelength) encountered a neutron star?

2 votes
2 answers
205 views

Can I state that a spacetime is homogeneous and isotropic iff $\nabla_\mu R = 0$?

1 vote
0 answers
63 views

Fractional derivatives in physics? [duplicate]

1 vote
2 answers
119 views

Question on Index Gymnastics

1 vote
0 answers
61 views

What distinguishes time directions from spacial directions?

1 vote
1 answer
131 views

Are the "extra dimensions" in string theory universal?

1 vote
2 answers
188 views

Calculation of the temperature of the Sun's core? Why is this value so low?

1 vote
4 answers
194 views

Can $G$ (Newton's constant) be thought of as a fundamental parameter of physics? [closed]

1 vote
2 answers
350 views

Expected observation if one assumes that light is a wave instead of a particle in the photoelectric effect

1 vote
0 answers
62 views

Negative sign in calculating the equation of motion of a free particle

1 vote
0 answers
170 views

Different way to demonstrate the equivalence of Nambu-Goto to Polyakov action?

1 vote
0 answers
92 views

derivative of a metric in a target space with respect to string coordinates

1 vote
1 answer
134 views

What should I do with $\frac{\partial x'^\lambda}{\partial x'^\mu}$ in a Gauge transformation in GR?

1 vote
0 answers
188 views

Einstein summation convention: What am I missing here? [closed]

0 votes
1 answer
203 views

Why don't we write the symmetric term $\eta_{\mu\nu}\partial_\rho\xi^\rho$ in a change of coordinates in linearized gravity?

0 votes
1 answer
72 views

Why does $\delta g^{\mu\nu}=0$ on a boundary imply that the tangential derivative of $\delta g^{\mu\nu}=0$ too?

0 votes
1 answer
96 views

Why do all the uncertainty relations have the units of action?