Ultralight Dark Photon and Casimir Effect Alizzi, Abdaljalel; Silagadze, Z. K.
International journal of theoretical physics,
02/2022, Letnik:
61, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We investigate the influence of a dark photon on the Casimir effect and calculate the corresponding leading contribution to the Casimir energy. For expected magnitudes of the photon - dark photon ...mixing parameter, the influence turns out to be negligible. The plasmon dispersion relation is also not noticeably modified by the presence of a dark photon.
A fast leading-order Monte Carlo generator for the process
e
+
e
-
→
μ
+
μ
-
γ
is described. In fact, using the
e
+
e
-
→
μ
+
μ
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γ
process as an example, we provide a pedagogical demonstration of ...how a Monte Carlo generator can be created from scratch. The
e
+
e
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→
μ
+
μ
-
γ
process was chosen, since in this case we are not faced with either too trivial or too difficult a task. Matrix elements are calculated using the helicity amplitude method. Monte Carlo algorithm uses the acceptance–rejection method with an appropriately chosen simplified distribution that can be generated using an efficient algorithm. We provide a detailed pedagogical exposition of both the helicity amplitude method and the Monte Carlo technique, which we hope will be useful for high energy physics students.
It is believed that an asteroid/comet impact 65 million years ago ended the dinosaur era. The researchers named the corresponding impact crater Chicxulub, the Mayan word roughly translated as “the ...dragon's tail.” We estimate the expected magnitudes of the Schumann resonance fields immediately after the Chicxulub impact and show that they exceed their present-day values by about 5×104 times. Long-term distortion of the Schumann resonance parameters is also expected due to the environmental impact of the Chicxulub event. If Schumann resonances play a regulatory biological role, as some studies indicate, it is possible that the excitation and distortion of Schumann resonances after the asteroid/comet impact was a possible stress factor, which, among other stress factors associated with the impact, contributed to the demise of dinosaurs.
•Expected magnitudes of the Schumann resonances after the Chicxulub impact are estimated.•Biological effects of ELF electromagnetic fields are reviewed.•Excitation and distortion of the Schumann resonances are considered as a stressor contributing to the dinosaur demise.
On arXiv moderation system Silagadze, Z.K.
Journal of informetrics,
August 2023, 2023-08-00, Letnik:
17, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The advent of arXiv has revolutionized scientific communication. However, its cultural significance goes far beyond simply accelerating scholarly communication. The arXiv gave a powerful impetus to ...the democratization of science, freeing young scientists and not only, especially from totalitarian countries, from authoritarian oppression. Many of arXiv's innovative features have been blurred by the introduction of a moderation system. Without a doubt, a moderation system is essential to maintain the quality of arXiv content. However, I believe that it can be improved in line with arXiv's original intentions, using the very successful experience of the MathOverflow moderation system.
•The present study provides insights into the arXiv moderation system.•The freedom of academic expression afforded by arXiv can be improved.•The inspiration from the MathOverflow moderation system can help in this goal.
•Ulmer and Kaissl formulas for the deconvolution of 1-D Gaussian kernels are generalized to the 3-dimensional case.•Scalar Hermite polynomials are expressed through ordinary Hermite polynomials.
...Ulmer and Kaissl formulas for the deconvolution of one-dimensional Gaussian kernels are generalized to the three-dimensional case. The generalization is based on the use of the scalar version of the Grad's multivariate Hermite polynomials which can be expressed through ordinary Hermite polynomials.
At first sight, arguments for and against the notion of relativistic mass look like a notorious intra-Lilliputian quarrel between Big-Endians (those who broke their eggs at the larger end) and ...Little-Endians. However, upon closer inspection we discover that the relativistic mass notion is alien to the spirit of modern physics to a much greater extent than it seems. To demonstrate an abyss between the modern approach and archaic notions, in this paper we explore how the concept of mass is introduced in modern physics. This modern approach reveals a deep cohomological origin of mass.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We calculate the electrostatic potential and electric field of a uniformly charged disk everywhere in space. This electrostatic problem was solved long ago, and its gravitational analogue was solved ...even earlier. However, it seems that physics students are not aware of the solution, because it is not presented in textbooks. The purpose of the present article is to fill this gap in the pedagogical literature.
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