Questions tagged [fine-tuning]
"Fine-tuning" is a situation in which the fundamental parameters in a theory must be "fine-tuned", i.e. precisely chosen, in order for a theory's predictions to agree with experimental data.
123 questions
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Tuning of bare parameters in RG and the Hierarchy Problem
From what I understand about Wilsonian RG, one of the key insights involved is that if you start with (say a scalar $\phi^4$) theory on a lattice and wish to define a meaningful continuum limit (which ...
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Cancellation of the quartic divergences in vector boson loop correction to Higgs mass
The vector boson loop corrections to the Higgs 2-point function are given by one diagram with one $hhVV$ vertex $ g_{hhVV} = 2im^2/v^2 $ and another diagram with two $hVV$ vertices $g_{hVV} = 2im^2/v$....
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Is there a reason that spectral lines are in the range of most Sun's black body radiation peak?
Our star acts as a black body of ~6000K. Conveniently, the range of light that it emits has many transitions of common molecular electron shells, which makes spectroscopy a thing, and also allows us ...
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Why does CKM matrix agree with mass hierarchy?
The CKM matrix: is almost diagonal. This means the matrix elements for quarks closest in mass have the biggest value or in other words, the mixing angles are relatively small. Is there a reason for ...
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What if we include a “zero-point energy” tensor in the EFEs? [duplicate]
The cosmological constant problem roughly states that the predicted value of $\Lambda$ becomes mostly infinite even though we only measure negligible values for it. In classic General Relativity, the ...
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Can the cosmological constant problem be solved by imposing that the renormalized value matches the observed value?
My understanding of the cosmological constant problem is that there is a difference of $\sim 120$ orders of magnitude between the value of the cosmological constant predicted by theoretical physics ...
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Why does the cosmological constant problem not cancel automatically?
The energy density of a free scalar field is: $$\rho_\text{bosonic} = \int^\xi_0{\frac{d^3k}{16\pi^3}\hbar\sqrt{c^2k^2 + \frac{m^2c^4}{\hbar^2}}}$$ Now, in the case of a Dirac field: $$\rho_\text{...
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Hierarchy Problem vs ratio of masses in the Standard Model
In the Standard Model, the ratio between the top quark's mass to the neutrinos is at least about $2 \times 10^{11}$. It could rise by at least an order of magnitude in the coming years as the ...
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The origin of the Hierarchy Problem
In the answer to this question on the origin of the hierarchy problem, it is stated that: The low-energy parameters such as the LHC-measured Higgs mass 125 GeV are complicated functions of the more ...
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Changing the frequency of the tuning forks
I just bought some tuning forks with frequencies of 128 Hz and 512 Hz. However, when I tested them using an app, their frequencies turned out to be lower than the specified values. How can I increase ...
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How solid state laser is tuned?
My understanding about solid state laser is sample as a source of exciting (lamp ,laser beam, ..) pump the crystal wich emite a certaine range of infrared wavelength sometime in visible range, this ...
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Cosmological Constant Problem calculations involving energy densities
I am following Timo Weigand lecutre notes on QFT, on page 28, he breifly touches on the Cosmological Constant Problem. But I am a little confused. He begins with a Lagrangian and include a nonzero $V_{...
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Perturbative calculation of hierarchy problem
I've been trying to understand the origin of the hierarchy problem for the Higgs mass but I've tied myself into some pretty nasty knots and I'm hoping someone can shed some light on this. So as I see ...
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3 votes
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Is the Higgs VEV unnatural?
Is there some way to argue that the Higgs VEV is unnatural, without even bringing up the Higgs boson mass? For example, can one show that the Higgs vev receives large corrections from new physics? The ...
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The "survival hypothesis" and supersymmetry
Tidying up my old papers I came across my supersymmetry notes from the late 80s. I thought I'd reread them. They may be out of date now. I find the mathematics somewhat comprehensible but not the ...
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