Questions tagged [casimir-effect]

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Considering the negative energy density in the Casimir effect and general relativity worm holes, are these experiments feasible?

The question came after I answered the question here, and reading the link provided where negative mass is needed to create wormholes, Microlensing by natural wormholes: theory and simulations We ...
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Is this solution for interstellar travel viable?

I have in mind a way to enable FTL travel. Is this way viable? In the paper: "Weighing the vacuum with the Archimedes experiment" we can see the dependency of the gravitational repulsion ...
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Do negative energies exist in the Standard Model?

As far as I understand, the Hamiltonian of QED and QCD are positive definite. The QED Hamiltonian in Coulomb Gauge is given by the following (credits David Tong QFT Notes): $$ H=\int d^{3} x\left[\...
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Why do we not observe a greater Casimir force than we do?

I am very new to quantum field theory, so forgive me if this question is a bit silly. The Casimir force is usually explained by the zero point energy of the field. You assume that the frequencies of ...
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Casimir effect - distance dependence

If one decreases the distance between the two plates in a Casimir configuration, the Casimir pressure is getting stronger. Can somebody give me an inuitive explanation why this is the case? Greetings
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Casimir energy in a circle for a scalar field with antiperiodic conditions

Following the section 2.3 of the book "Advances in the Casimir Effect" by M. Bordag, the Casimir energy is given, for a maseless field, by $$E(a) = E_0 (a) - E_{0M} (a)$$ where $E_0 (a)$ is ...
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Energy-momentum $T_{00}$ component for a scalar field in 2-dimensional spacetime

I'm reading the book "Advances in the Casimir Effect" by M. Bordag. In section 2.4 it says that the $00$-component of the energy-momentum tensor is given by (eq. 2.59): $$T_{00}(t,x)=\frac{\...
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Can the Casimir effect propel this system?

Between two extremely close metal plates, there is a force of attraction because the metal plates have to be nodes of any electromagnetic quantum fluctuations and so there are less virtual particles ...
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Does the region inside of buckyball have a slightly negative energy density due to the casimir effect?

I was considering a buckyball floating in a vacuum. It's surface is a strongly conducting surface and so I would expect some kind of Casimir effect to apply, i.e. the wavelength of virtual photons ...
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Should there be a Casimir effect for superconductors?

I was curious if a Casimir effect between superconductors makes sense theoretically and whether one has been detected experimentally. I found the following paper: arXiv:1902.09136 — which suggests ...
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Does the Casimir Effect Fluctuate?

I understand that two uncharged plates places nanometres apart experience a net force due to their interference with the quantized fields around them. I'm wondering whether or not this force ...
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Casimir energy vs Helmholtz free energy

In what way are the Casimir energy and Helmholtz free energy related / do they differ? In QFT one can compute the Helmholtz free energy as the vacuum expectation value of the zero point function. This ...
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Casimir effect and negative mass

The Casimir effect causes a limited number of wave functions, causing fewer particles between plates than outside and this could be considered as a negative mass. Then, if we have a technology good ...
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Using Casimir force as a thruster

In quantum mechanics, there is a phenomenon called the 'Casimir effect'. As two metal plates have a very small distance, the plates work as a potential well, causing limited wave function between the ...
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Electromagnetic field in the Casimir effect

So, I read, that the Casimir effect arises from the ground state of the electromagnetic field. But I don't understand where the electromagnetic field in the Casimir effect comes from, since we are ...
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Why do photons in the Casimir effect get destroyed when they collide with each other?

Shouldn't these photons create a stronger photon when they collide? If you shine a light at another light it gets stronger not destroyed. Why is it different in the Casimir effect case?
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Is there an analogue of the Casimir effect for gravity? [duplicate]

Having recently learned about the Casimir effect I began to wonder about spacetime and the effect of intervening bodies on gravitational forces: Does a mass have a "shadow" behind it or ...
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Casimir effect and law of conservation of energy

If we use a couple of plates and the casimir force attracts those plates, when the plates are close together, we reduce the surface area of the plates by pushing it downwards and then pull the plates ...
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Could a proton be produced using the dynamical Casimir effect?

According to the standard model, would it be theoretically possible to emit protons or other complex particles from the vacuum using the dynamical Casimir effect? Or is it only possible to emit ...
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How does gravity-spacetime interaction modulate the Casimir force? [closed]

Suppose there is a point source of strong gravity. Far away from this point source in terms of the speed of light, there exists a vacuum in space where no dust is. This vacuum nonetheless can ...
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Casimir Effect Analogue

The Casimir effect from what I understand is computed as the integral over a macroscopic object (e.g. a pair of conducting metal plates) of an essentially quantum phenomenon, namely the energy of the ...
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Casimir effect evidence

How does the attraction between two metal plates support a new effect (or force)? Isn't it expected that two plates attract each other due to the London dispersion? If so, how does the experiment ...
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Blocking quantum effects

A Faraday cage blocks electromagnetic fields, provided they are not intense enough to change the state to something non-conductive (e.g. slicing it in two with a laser). Is there any analogous system ...
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Producing negative mass in a realistic way

The Casimir effect produces a region of negative energy between two plates. Is it possible, at least theoretically and ignoring the practical consequences of the enormous force that implies, to ...
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Can real particles become virtual?

I know that virtual particles can become real for example with the dynamic Casimir Effect. But is the opposite also possible? I.e. can real particles become virtual?
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Does the Casimir effect violate the Generalized Second Law of Thermodynamics?

In order to avoid violation of the Generalized Second Law of Thermodynamics by classical non-minimally coupled scalar fields, Ford et al demonstrated that the quantum inequalities prevent the negative ...
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Is it possible to produce Fermions from the dynamical Casimir effect?

As I understand it, the dynamical Casimir effect has been demonstrated in the laboratory and has been found to allow the emission of photons from the vacuum. Given the right frequency of the ...
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Vacuum energy conversion (to heat)

Two metal plates placed close together in vacuum will collide due to more and more vacuum (electromagnetic) energy being converted from quantum EM modes to kinetic energy of the plates because of the ...
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Could the Casimir effect be bad science?

Could the Casimir effect be due to incident light used to observe the effect during the experiments? It seems to me that the effect occurs because of the photoelectric effect because the conditions to ...
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Casimir Force and bosonic String Theory dimensions

I was reading the lecture notes on Quantum field theory by David Tong. In the section on Casimir force he derived the force of attraction felt by the plates due to the field vacuum energy in $1+1$ ...
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Is the Casimir energy in CFT an observable?

We know that if we transform a 2d conformal field theory from a plane to a cylinder with perimeter $L$, the ground state energy will be shifted by $$E = -\frac{c}{24L}$$ due to the Schwarzian ...
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What's the current status of the Casimir force $\leftrightarrow$ vacuum energy controversy?

Most textbooks explain the Casimir force by using the infinitely large ground state energy associated with quantum fields. Since the total energy between two conducting plates is different from the ...
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An interesting Casimir configuration [duplicate]

A problem related to an interesting Casimir configuration.  I have the following configuration , related to a modified Casimir experiment.  We have two parallel metal plates and an orthogonal ...
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Solving a Casimir configuration, the U - bracket

A problem related to an interesting Casimir configuration.  I have the following configuration, related to a modified Casimir experiment.  We have two parallel metal plates and an orthogonal metal ...
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Poor man's Alcubierre drive?

In general relativity,  the fundamental notions are the curvature (Ricci tensor) and the stress energy tensor. Energy density and curvature are connected .  The Casimir vacuum between parallel plates ...
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Would a planet with mirror surface emit radiation due to dynamical Casimir effect? If so, where the energy would come from?

The dynamical casimir effect tells that an accelerating mirror should produce photons. Due to equivalence principle a mirror in uniform gravitational field also should produce photons. So, should a ...
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Do the apparent Black Hole dimensions contract as the observer falls into Black Hole?

According the Special Relativity, all objects contract their length if moving fast. As the observer falls into black hole, his relative speed to it increases up to the speed of light. But from his ...
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Casimir Effect for other interactions

I read about the Casimir and dynamical Casimir effect. However it is always mentioned in the context of electromagnetism and with two perfectly conducting plates. My question is whether there can be a ...
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Does energy conservation apply to Casimir effect?

If you cancel out some quantum field modes using two 'Casimir' plates you decrease the average energy density in the region and gain potential energy in Casimir force approximately proportional to the ...
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Why Casimir effect moves plates in water?

If two plates are put partly in waving water parallel to each other, there will be less wavelengths between the plates than elsewhere and this will cause the plates to move towards each other. Why do ...
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What does Pauli-Villars Regularization physically mean?

Calculating loop correlators, Pauli-Villars regularization is introduced to avoid divergence. It is to cut off the high frequency(loop-momentum) contribution. Thus a question naturally arises. Why is ...
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Hawking radiation from black hole inside a Casimir cavity

Would a black hole inside a Casimir cavity emit Hawking radiation more slowly than a black hole outside a Casimir cavity? Various descriptions of each phenomena involve either virtual particles or ...
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Does light travel faster in between Casimir plates?

Speed of light is in general $c/n$ where $n$ is a refractive index. But for example introducing two parallel plates with very small spatial separation will perturb the energy density of vacuum ...
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Casimir Force and Electric Field?

I found the wiki article a bit misleading because I took $<\mathbf{E}>$ as an electric field... the equation in question is $$\frac{F}{A} = -\frac{d}{da} \frac{<\mathbf{E}>}{A} = - \frac{\...
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Vacuum energy length scale detectable by Casimir effect?

According to Sean Carroll's The Cosmological constant (Eqn.20) cosmological observations imply that the magnitude of the vacuum energy density in natural units is given by $$|\rho^{(obs)}_\Lambda|\le (...
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Casimir effect - gravitational influence?

Regarding the Casimir effect, is gravitational attraction too weak in order to explain the attraction between the plates?
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Casimir effect in the double slit experiment

Has anyone to your knowledge, ever detected, or perhaps just tried to detect, a Casimir effect between the plate (with the slits) and the screen behind in the double slit experiment?
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Arranging coefficients in a derivation of the Casimir energy

I'm working on the derivation of the Casimir energy from quantum field theory. From the K-G equation (with $c=1$ and $\hbar=1)$ I found the vacuum energy: $$\langle 0|H|0\rangle=E_{vac}=V\int_{-\...
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Casimir effect - constraint of wave length on photons and virtual photons

In Casimir effect, I would like to know, maybe from Quantum Field Theory, why the photons (and virtual photons) have to check the relation $L=n\lambda\,$ with $n>0$ to be considered as present ...
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How is Casimir effect related to String theory?

I'm looking at the Casimir effect calculation. As I understand it, it says that because wavelengths can only take on discrete values between two sheets there is a difference in the energy of the ...