Questions tagged [reissner-nordstrom-metric]
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Can a Black hole only have negative EM charge?
I understand that Black holes can have EM charge, they can have EM fields around them.
But is that possible that a black hole has more positrons and protons inside it (or that these have more EM ...
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1answer
127 views
Irreducible mass of a charged black hole merger
The irreducible mass $ \rm m_{irr} $ of a black hole with charge $ \rm Q $ is (in natural units)
$$ \rm m_{irr} = \frac{r_{+}}{2} = \frac{M}{2} + \sqrt{\frac{M^2}{4} - \frac{Q^2}{4}} $$
which is ...
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1answer
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Imaginary charge on black hole
I was wondering if one can put an imaginary charge on a black hole. What I mean is, take a Reissner-Nordstörm black hole and make the charge $Q$ and therefore also the imaginary potential pure ...
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1answer
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What is the reason for $g_{tt}g_{rr}=-1$?
Both Reissner Nordstrom and Schwarzschild solutions in GR exhibit the property that $g_{tt}g_{rr}=-1$.
What can we deduce from this property in terms of the gravitational field?
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On destroying the horizon of a Reissner-Nordstrom black hole
Consider a Reissner-Nordstrom black hole with $Q<M$, so that it has a well defined event horizon, the metric for such a black hole is given by (for $\theta=0, and ~d\phi=0$):
$$ds^{2}~=~-g(r)dt^{2}+...
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Naked Singularities Out of Extremal Black Holes?
Consider a pair of identical Extremal Black holes at rest. It is a fact that they exert no net force on each other and remain in a static equilibrium. Now, clearly, each of the black holes is in ...
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1answer
445 views
Why Do Extremal Black Holes Not Radiate?
This might be a "meta physical" question with no actual physics content and if such is the case then I apologize. Actually, to figure out whether or not it is an actual physics question is one of the ...
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1answer
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Gravitational and electromagnetic radiation from collision of Kerr-Newman black holes
When black holes collide, they produce a gravitational wave, as has been recently established by LIGO.
When a charge is accelerated, it creates an electromagnetic wave.
Does an accelerated massive ...
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2answers
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Does the Reissner Nordstrom Metric Necessarily Represent a Charged Black-hole?
The Reissner Nordstrom metric
$$ds^2 = - \bigg(1-\dfrac{2M}{r}+\dfrac{4\pi Q^2}{r^2}\bigg)dt^2 + \dfrac{1}{\bigg(1-\dfrac{2M}{r}+\dfrac{4\pi Q^2}{r^2}\bigg)} dr^2 + r^2 d\Omega_2^2 $$
is a solution ...
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0answers
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Temperature of R-N Black Hole by Euclideanising the Metric [closed]
How to derive the temperature of the Reissner–Nordstrom black hole by euclideanising the metric?
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Reissner Nordstrom Metric with Non-vanishing Cosmological Constant
What is the generalisation of the Reissner–Nordstrom metric to a situation in which the cosmological constant does not vanish?
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2answers
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Would two Reissner-Nordstrom black holes with like charges repel or attract?
A few related side questions:
If the two oppositely-charged Reissner Nordstrom black holes collide
would their charge be negated and result in a regular Schwartzchild black hole?
Would a positively-...
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2answers
72 views
Is it possible to turn a RN black hole with real r+- into one with naked singularity?
Let's say we initially have a RN black hole that has $Q^2<M^2$ where $Q$ and $M$ are its charge and mass respectively. Now if a particle goes into the blackhole is it possible for the new charge ...
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2answers
276 views
Electromagnetic tensor trouble understanding
I'm running into trouble understanding what is going wrong, fooling around with the maxwell equations in tensor form, and playing with Cartesian and spherical coordinates.
To be more clear, I'm ...
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0answers
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Einstein Maxwell Lagrangian
If I take the Lagrangian
\begin{eqnarray} L= \frac{1}{2} R *1 - \frac{1}{2} F\wedge *F
\end{eqnarray}
I found $$ds^2 = -(1-\frac{2M}{R} +\frac{Q^2}{2r^2} )dt^2 + (1-\frac{2M}{R} +\frac{Q^2}{2r^2}...
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1answer
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Physical interpretation of the Reissner-Nordstrom metric for the special case
In the Reissner-Nordstrom metric
$$ \mathrm ds^2 = \left(1 - \frac{2GM}{r} + \frac{GQ^2}{4\pi\epsilon_0 r^2}\right)~\mathrm dt^2 - \left(1 - \frac{2GM}{r} + \frac{GQ^2}{4\pi\epsilon_0 r^2}\right)^{-1}...
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1answer
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Does the cosmic censorship conjecture limit the charge/mass ratio for particles?
For charged black holes, supposing true the cosmic censorship conjecture, this inequality must be verified (in natural units):
$GM^2 > Q^2$
Where of course $M$ and $Q$ are the mass and charge of ...
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2answers
283 views
Does the charge of a black hole affect its space-time geometry?
Does a black-hole of a given mass and angular momentum have the same space-time geometry regardless of its charge? I'm pretty sure that an electric field can accelerate a charged particle but doesn't ...
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2answers
943 views
Derivation for the temperature of Reissner-Nordström (charged) black hole
A lot of the text for this is from "How does one correctly interpret the behavior of the heat capacity of a charged black hole?" but this concerns a different question. The Reissner-Nordström black ...
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1answer
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Physical interpretation of the Reissner-Nordstrom metric
The Reissner-Nordstrom metric (in spherical coordinates and c = 1) differs from the Schwarzschild metric in a additive term $$\frac{GQ^2}{4\pi\epsilon_0 r^2}$$, so the metric is
$$ds^2 = \left(1 - \...
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0answers
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What is the difference between Reissner-Nordstrom (RN) black hole and dyonic black hole?
A RN black hole is a black hole with electric charge, and a dyonic black hole with both electric charge and magnetic charge.
My Questions:
Is the above statement correct?
Is the charges the unique ...
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2answers
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Physical motivation for mathematically extending solutions to Einstein's equations
Sorry if this question gets a little long; I want to explain why I'm asking it.
The usual Schwarzchild metric
$$ds^2 = -\left(1-\frac{2M}{r}\right) dt^2 + \left(1-\frac{2M}{r}\right)^{-1} dr^2 + r^2(...
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1answer
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What is unstable about the wormhole in the Reissner-Nordström solution?
In the conformal diagram for the Reissner-Nordström solution (included below), the inner horizon of the black hole leads to a wormhole which has a singularity, but it is possible to exit it through a ...
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1answer
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Singularities in the Reissner–Nordström metric
I am doing a presentation on black holes but I'm having trouble finding information on the Reissner–Nordström metric. From the metric
$$\textrm{d}s^2=\left(1-\frac{R_S}{r}+\frac{R_Q^2}{r^2}\right)c^2\...
1
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1answer
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EM Field tensor of a point charge [closed]
If I say the Reissner-Nordstrom metric
$$
ds^2=-\left(1-\frac{2m}{r}+\frac{e^2}{r^2}\right)\text d t^2 + \left( 1-\frac{2m}{r}+\frac{e^2}{r^2}\right)^{-1}\text d r^2 + r^2 \text d \Omega^2
$$
is the ...
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0answers
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Reissner-Nordström Black Holes
The Reissner-Nordström black holes are described by the metric,
\begin{align}
ds^2 = -\left(1-\frac{2M}{r}+\frac{Q^2}{r^2}\right)dt^2 + \frac{1}{1-\frac{2M}{r}+\frac{Q^2}{r^2}}+r^2d\Omega^2
\end{...
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2answers
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Do black holes have charges?
Do black holes have charges? If so, how would they be measured? Also, does electricity behave the same way? Black holes affect photons, which are carriers of EM radiation, so do black holes have any ...
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1answer
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Diving into a charged (Reissner-Nordstrom) Black hole
Apparently there are two event horizons in this type of black hole, where the second one is known as the Cauchy horizon. According to Carroll, if you go into the first one, you will fall until you ...
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Can a nearly-extremal black hole be stable against Schwinger vacuum breakdown?
I was doing some basic algebra to estimate the range of possible masses $M$ and electric charge $Q$ for a nearly extremal Reissner-Noström black hole. I want to see if the logic is correct
the ...
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2answers
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Is the Hawking radiation of a charged black hole thermal?
Suppose you have a Schwarzschild black hole of mass $M$ and angular parameter $a = 0$ (no rotation).
Question: is it possible to throw a charge $Q$ at a faster rate than it will be re-radiated? Will ...
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2answers
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What role does electrical charge play in black holes?
Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes — as they are popularly portrayed — as being true for black ...
