Questions tagged [unruh-effect]

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Are Bremsstrahlung and the Unruh effect equivalent?

This paper argues that the absorption and emission rates from and to the thermal Unruh bath of a proton viewed in a coaccelerated frame is equal to the emission rated viewed from an inertial observer. ...
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What are zero-energy Rindler photons?

In the discussion of the Unruh effect and Bremsstrahlung (e.g. here) I always come across "zero-energy Rindler photons". What exactly are these? Shouldn't a zero-energy photon correspond to a static ...
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Why to we take the Minkowski vacuum to calculate the thermal Unruh distribution?

Looking at a derivation for the Unruh effect, this generally ends with a calculation of the particle distrubution: $$\langle{0_M}|b^\dagger b|0_M\rangle=\frac{1}{e^{\hbar\omega/k_BT_U}-1}$$ where $b$ ...
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Do Rindler horizons evaporate?

It is thought that black holes radiate via Hawking radiation and consequently evaporate. Rindler horizons too emit radiation. Are they also thought to undergo a similar process of evaporation?
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Question about path integral step of the rindler decomposition

In most papers where I've read about Rindler decomposition and the Unruh effect ( see for example [1] or [2]) they start by saying that they want to find the wavefunction of the vacuum state in the ...
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Why accelerating observer can see Unruh radiation?

I read that uncertainty principle allows a pair of virtual particles to spawn in a vacuum as long as time is $h/E$ and nature forbid negative energy to exist, a accelerating person will see the photon ...
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Does a person falling into a black hole “see” the black hole? [duplicate]

For a person not falling into a black hole they must be accelerating. They will see a black hole event horizon with Hawking radiation coming out of it. For a free-falling person falling into a black ...
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Does thermal state in Rindler spacetime correspond to Minkowski vacuum?

We know that the Minkowski vacuum corresponds to the thermal state in a Rindler wedge at Unruh temp. But does the thermal state in one Rindler wedge at Unruh temperature uniquely map to the Minkowski ...
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Rindler-Fulling Quantization - Rindler mode expansion of $\phi$: why are we ignoring the Past and Future Wedges?

I am following along Chapter 2 of Takagi's Vacuum noise and stress induced by uniform accelerator. I am at the point of performing the Rindler-Fulling Quantization of a real scalar field, where you ...
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Can an Observer Distinguish between Unruh Effect and Hawking Radiation by Measuring Temperature?

In Unruh effect, the temperature of background appears to be proportional to acceleration. On the other hand, the temperature of a black hole is inversely proportional to its mass. If the two ...
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Big Rip: will cosmic event horizon's Unruh radiation balance accelerating expansion?

The way I've seen the expansion of the universe described, it seems to work a bit like an inside-out black hole: an event horizon beyond which there is no causal connection, light from beyond it can't ...
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What conceivable connection is there between the cosmological constant and radius of the Universe?

You probably noticed that the radius of the (observable) Universe in Planck lengths $R$ (about $10^{60}$) and the cosmological constant $\Lambda$ (about $10^{-120}$) in natural units obey ...
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Why doesn't an observer at rest on the Earth see Unruh radiation? [duplicate]

It is well know that QFT predicts that an accelerated observer would see Unruh radiation. This is related to the presence of a Rindler horizon and leads to the conclusion that an inertial and an ...
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Is there a satisfactory resolution to the Rotating Detector Puzzle?

The Rotating Detector Puzzle refers to the dilemma when trying to study how a rotating detector interacts with the background vacuum. The trail of literature that I found are these papers: p1, p2, p3, ...
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What is the effect of the locality condition if a „Rindler observer“ hovers close to a black hole?

Consider a „Rindler observer“ hovering close to the event horizon of a black hole, whereby flat spacetime is assumed locally. Does this observer see the same Unruh radiation like a Rindler observer ...
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Why does the Unruh effect not cause a physical contradiction?

If the Unruh effect says that the temperature of space depends on one's acceleration, such that an accelerating observer will observe that hir vacuum consists of a thermal bath at some elevated ...
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Hawking Radiation of normal gravitational field

If the event horizon of a black hole can radiate, then is it possible that normal gravitational field also radiates? The radiation will probably be very low, but still there could be some. Also by ...
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Schwinger effect verified by Unruh temperature?

According to https://arxiv.org/abs/1407.4569, equation.(2.15), the Schwinger electron-positron pair production rate in Minkowski space, $N_S$, is given in natural units by $$N_S\sim\exp(-\frac{m}{2T_U}...
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Electromagnetic Unruh/Hawking effect? (Improved argument) [closed]

This is an improved version of the argument in Electromagnetic Unruh effect? In the quantum vacuum particle pairs, with total energy $E_x$, can come into existence provided they annihilate within a ...
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Electromagnetic Unruh effect?

The Unruh temperature is given by $$T=\frac{\hbar\ a}{2\pi c k_B}.$$ If we have an electron field with charge $e$ and mass $m_e$ acted on by an electromagnetic field $\vec{E}$ then very naively maybe ...
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Lorentz transform in Unruh effect

I'm re-reading about the Unruh effect and while I broadly understand the concept of plugging through the coordinate transform and the Bogoliubov transformation, I'm curious as to whether there is a ...
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What is the Unruh temperature for an observer at near the speed of light?

I have read about the Unruh effect where an accelerated observer would experience a radiation that a non accelerated observer wouldn't. According to wikipedia the formula goes like this: My question ...
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Is there any relation between Casimir effect and Unruh radiation?

I hope this question is appropriate for this site. The question refers to the link: https://arxiv.org/abs/1302.2775 where it proposes that: Abstract: The property of inertia has never been fully ...
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Unruh effect and string theory?

My sincere apology if this question is not appropriate for this forum. Recently, I came across the Unruh radiation or Unruh effect. From the Wikipedia page https://en.wikipedia.org/wiki/Unruh_effect ...
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The relation between the Unruh effect and the Ehrenfest-Tolman effect

I am interested in the relation and, perhaps, the equivalence between two effects to do with temperature and gravity. The first one, the Unruh effect, states that the background black-body radiation, ...
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Existence of the Unruh effect

In the paper Quantum field aspect of Unruh problem (and others with similar approaches) the author shows that applying the rigorous algebraic approach to QFT, the derivation of the Unruh effect ...
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What does an accelerated body's *interaction* with Unruh radiation look like in an inertial frame?

(Note: I'm only considering flat spacetime in this question.) The Unruh effect is that the quantum state that looks like the vacuum in an inertial frame looks like a thermal bath of particles in a ...
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Why acceleration at the edge of the galaxy is lesser?

I was going through Modified Inertia using the Hubble Scale Casimir effect the theory is proposed by M.E. McCulloch. The theory says it can explain different anomalies such as EmDrive, Galactic edges,...
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Unruh effect, temperature and energy density

The Unruh effect basically states that an accelerated observer will see warm gas of particles following a blackbody distribution with some temperature T, where as an inertial observer would see none. ...
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Can I view all Bogoliubov transformations as frames in space-time?

I have recently learned about the Unruh effect and the fact that when going from a stationary to an accelerated reference frame the quantum state is updated by a Bogoliubov transformation. Does every ...
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If I spin around why do the stars not dissappear?

Galaxies at the far limit of the visible universe are moving away from us near the speed of light. There may be some beyond that that are moving away from us faster, so the universe appears to have an ...
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Why do we only detect Minkowski particles?

I'm having trouble building intuition of the Unruh effect, altough I can follow the proof using Bogoliubov transformations. When studying a massless scalar field in 1+1D QFT, we start from the ...
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Literature for cyclicity in Unruh effect

On this Wikipedia page on Unruh effect, there's the equation $e^{2 \pi i H}=1$. Here, $H$ is the Lorentz boost hamiltonian. I've read some literature on KMS states and Bisognano-Wichmann theorem, ...
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Is Hawking radiation really the same as Unruh radiation

I read that Hawking radiation is the same as Unruh radiation. However, there seems to be a paradox here. If you have an extreme black hole (say with maximum charge), then it has temperature 0 and ...
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Can the fact that the vacuum energy in curved spacetime is not boost invariant be explained without mathematics?

I read in an answer to a question if Hawking radiation can be explained without too much mathematics that this is impossible insofar the vacuum energy is not boost invariant in a curved spacetime. ...
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An explanation of Hawking Radiation

Could someone please provide an explanation for the origin of Hawking Radiation? (Ideally someone who I have been speaking with on the h-bar) Any advanced maths beyond basic calculus will most ...
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Dark energy and virtual particles

If space time is accelerating away from itself everywhere due to dark energy, could this acceleration be the cause of virtual particles, essentially Unruh radiation?
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A conformal mapping between a Rindler Wedge and a causal diamond. What is the right map and how do I see it does what is expected?

I am going through the calculations in arXiv:1312.7856. These involve a conformal map between the Minkowski Rindler Wedge ($\mathcal{R}$), given by $X^1 \geq 0,X^+\geq 0,X^-\geq 0 \quad$ (with $X^{\...
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Quantization on Minkowski/Schwarzschild spacetimes based on unusual surface

I'm reading the book of Wald "Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics", and I'm pondering on this problem: In Minkowski spacetime, we usually quantize our fields with ...
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Does any ordinary object emit radiation due to Unruh effect and equivalence principle? [duplicate]

I am just wondering is there Hawking radiation for any object (that has mass) due to its gravity. Base on the Unruh effect and equivalence principle, any object should emit Black-body radiation or ...
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Unruh radiation in a rotating frame

Unruh radiation normally applies to linearly accelerated frames Is there an equivalent of the Unruh thermal radiation in a frame that is spinning? I am not aware of any horizon being created from a ...
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Why is it that black holes emit Hawking radiation? [duplicate]

Black holes are basically neutron stars with such a gravitational force that even light cannot escape from it. But what causes it to emit Hawking radiation?
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Unruh radiation and conservation of energy

Consider the Minkowski spacetime filled by some fields in their Minkowskian vaccum state. Now consider a Rindler observer carrying with him, say, one liter of water. According to Unruh formula, the ...
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Unruh effect and relative acceleration

This is how I understand the Unruh effect: if a person (say, Bob) is moving with acceleration $a$ in his spaceship, then he will see an apparent event horizon around him--that is, the vacuum will ...
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Does the Unruh effect really describe a thermal bath?

If we consider a free (massless scalar) field $\phi$ in Minkowski space and look at it in Rindler coordinates (which correspond to what an accelerated observer sees), we find that the action of the ...
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Why does the $\Lambda\mathrm{CDM}$ model end up a cold de Sitter space?

If space-time is expanding at $a(t)=e^{Ht}$, you plug acceleration into the Hawking-Unruh temperature equation, solve for time, and get the cosmic horizon at the Planck temperature within about $4.4 \...
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Can the Unruh effect be confirmed by the LHC?

Two short questions regarding the Unruh effect. There are related answers on this forum and on wikipedia, but I am looking for confirmation of my own intuitive assumptions, so a straightfoward yes or ...
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What is the essence of the Unruh-effect?

The essence of the Unruh effect is basically that coordinate-transformations lead to different excitations/occupation numbers of the quantum fields. Is that statement correct? So in QFT, while an ...
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Is there an equivalent of Rindler coordinates for an object in centripetal motion?

Rindler coordinates are a parametrization of (a subset of) Minkowski space that are "natural" for an object experiencing constant acceleration - more specifically, an object experiencing constant ...
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The particle content of a given state

In Carroll's we read ...The Unruh effect teaches us the most important lesson of Quantum Field Theory (QFT) in curved spacetime, the idea that "vacuum" and "particles" are observer-dependent ...