arXiv subjects

Janning Meinert

Publications and source records attributed to Janning Meinert.

6 recordsLinked to original sources

arXiv2024

Electroweak parameters from mixed SU(2) Yang-Mills Thermodynamics

Based on the thermal phase structure of pure SU(2) quantum Yang-Mills theory, we describe the electron at rest as an extended particle, a droplet of radius $r_0\sim a_0$, where $a_0$ is the Bohr radius. This droplet is of vanishing pressure and traps a monopole within its bulk at a temperature of $T_c=7.95$ keV. The monopole is the Bogomolny-Prasad-Sommerfield (BPS) limit. It is interpreted in an electric-magnetically dual way. Utilizing a spherical mirror-charge construction, we approximate the droplet's charge at a value of the electromagnetic fine-structure constant $\alpha$ of $\alpha^{-1}\sim 134$ for soft external probes. It is shown that the droplet does not exhibit an electric dipole or quadrupole moment due to averages of its far-field electric potential over monopole positions. We also calculate the mixing angle $\theta_{\rm W}\sim 30^{\circ}$ which belongs to deconfining phases of two SU(2) gauge theories of very distinct Yang-Mills scales ($\Lambda_{\rm e}=3.6\,$keV and $\Lambda_{\rm CMB}\sim 10^{-4}\,$eV). Here, the condition that the droplet's bulk thermodynamics is stable determines the value of $\theta_W$. The core radius of the monopole, whose inverse equals the droplet's mass in natural units, is about 1% of $r_0$.

hep-th↗

arXiv2023

Modified temperature redshift relation and UHECR propagation

We re-examine the interactions of ultra-high energy cosmic rays (UHECRs) with photons from the cosmic microwave background (CMB) under a changed, locally non-linear temperature redshift relation $T(z)$. This changed temperature redshift relation has recently been suggested by the postulate of subjecting thermalised and isotropic photon gases such as the CMB to an SU(2) rather than a U(1) gauge group. This modification of $\Lambda$CDM is called SU(2)$_{\rm CMB}$, and some cosmological parameters obtained by SU(2)$_{\rm CMB}$ seem to be in better agreement with local measurements of the same quantities, in particular $H_0$ and S$_8$. In this work, we apply the reduced CMB photon density under SU(2)$_{\rm CMB}$ to the propagation of UHECRs. This leads to a higher UHECR flux just below the ankle in the cosmic ray spectrum and slightly more cosmogenic neutrinos under otherwise equal conditions for emission and propagation. Most prominently, the proton flux is significantly increased below the ankle ($5\times10^{18}$ eV) for hard injection spectra and without considering the effects of magnetic fields. The reduction in CMB photon density also favours a decreased cosmic ray source evolution than the best fit using $\Lambda$CDM. In consequence, it seems that SU(2)$_{\rm CMB}$ favours sources that evolve as the star formation rate (SFR), like starburst galaxies (SBG) and gamma-ray bursts (GRB), over active galactic nuclei (AGNs) as origins of UHECRs. We conclude that the question about the nature of primary sources of UHECRs is directly affected by the assumed temperature redshift relation of the CMB.

astro-ph.HE↗

arXiv2023

Frequency-redshift relation of the Cosmic Microwave Background

We point out that a modified temperature-redshift relation ($T$-$z$ relation) of the cosmic microwave background (CMB) can not be deduced by any observational method that appeals to an a priori thermalisation to the CMB temperature $T$ of the excited states in a probe environment of independently determined redshift $z$. For example, this applies to quasar-light absorption by a damped Lyman-alpha system due to atomic as well as ionic fine-splitting transitions or molecular rotational bands. Similarly, the thermal Sunyaev-Zel'dovich (thSZ) effect cannot be used to extract the CMB's $T$-$z$ relation. This is because the relative line strengths between ground and excited states in the former and the CMB spectral distortion in the latter case both depend, apart from environment specific normalisations, solely on the dimensionless spectral variable $x=\frac{h\nu}{k_B T}$. Since literature on extractions of the CMB's $T$-$z$ relation always assumes (i) $\nu(z)=(1+z)\nu(z=0)$ where $\nu(z=0)$ is the observed frequency in the heliocentric rest frame, the finding (ii) $T(z)=(1+z)T(z=0)$ just confirms the expected blackbody nature of the interacting CMB at $z>0$. In contrast to emission of isolated, directed radiation, whose frequency-redshift relation ($\nu$-$z$ relation) is subject to (i), a non-conventional $\nu$-$z$ relation $\nu(z)=f(z)\nu(z=0)$ of pure, isotropic blackbody radiation, subject to adiabatically slow cosmic expansion, necessarily has to follow that of the $T$-$z$ relation $T(z)=f(z)T(z=0)$ and vice versa. In general, the function $f(z)$ is determined by energy conservation of the CMB fluid in a Friedmann-Lemaitre-Robertson-Walker universe. If the pure CMB is subject to an SU(2) rather than a U(1) gauge principle, then $f(z)= \left({1/4}\right)^{1/3}(1+z)$ for $z\gg 1$, and $f(z)$ is nonlinear for $z\sim 1$.

hep-th↗

arXiv2022

Cosmological parameters from Planck data in SU(2)$_{\rm CMB}$, their local $\Lambda$CDM values, and the modified photon Boltzmann equation

A review of the spatially flat cosmological model SU(2)$_{\rm CMB}$, minimally induced by the postulate that the Cosmic Microwave Background (CMB) is subject to an SU(2) rather than a U(1) gauge principle, is given. Cosmological parameter values, which are determined from the Planck CMB power spectra at small angular scales, are compared to their values in spatially flat $\Lambda$CDM from both local and global extractions. As a global model SU(2)$_{\rm CMB}$ leans towards local $\Lambda$CDM cosmology and is in tension with some global $\Lambda$CDM parameter values. We present spectral antiscreening / screening effects in SU(2)$_{\rm CMB}$ radiance within the Rayleigh-Jeans regime in dependence on temperature and frequency. Such radiance anomalies can cause CMB large-angle anomalies. Therefore, it is pointed out how SU(2)$_{\rm CMB}$ modifies the Boltzmann equation for the perturbations of the photon phase space distribution at low redshift and why this requires to the solve the $\ell$-hierarchy on a comoving momentum grid ($q$-grid) for all $z$.

hep-th↗

arXiv2021

Condensates of ultralight axions and a link of leptonic scales to dark matter

The mass of ultralight axions is determined in order to get the explicit U(1)$_A$ symmetry breaking scale $ Λ$ at a Peccei-Quinn scale of the magnitude of the Planck mass. It is assumed that the dominant contribution to the mass of a galaxy with low surface brightness is only determined by one axionic species in the sense of fuzzy dark matter (lumps). For rotation curve fits to galactic rotation curves, therefore the Soliton-Navarro-Frenk-White model is used, which assumes a condensate core plus correlated axions in the halo according to the solution of the Poisson-Schrödinger system. In addition, three commonly used mass density profiles are considered: Navarro-Frenk-White, pseudo-isothermal and the Burkert model. An axion mass $m_a$ of $0.675\times10^{-23}\,$eV is extracted, which reproduces previous results in the literature. This implies an effective Yang-Mills scale of $Λ\sim 287\,$ eV, which is only a factor of $15$ smaller than the Yang-Mills scale of an SU(2) theory that is used to describe the first lepton family. The cosmological model SU(2)$_{\rm CMB} $ suggests that three SU(2) Yang-Mills theories, each for the formation of the lepton doublets (e,$ν_e$), ($μ$,$ν_μ$), and ($τ$,$ν_τ$) are equally responsible for contributing to the current density of dark matter. Parameters of an isolated lump, such as the gravitational Bohr radius or the virial mass, are determined solely by the Planck mass and the corresponding lepton mass. If the dominant constituent of the dark mass contained in a galaxy is represented by e-lumps, a mixture of $ τ- $ and $ μ$-lumps could possibly explain the presence of massive compact objects in galactic centers, and $ τ$-lumps could be related to globular clusters and the halo mass. This might provide a theoretical explanation for the mass gap between stellar and super massive black holes.

hep-ph↗

arXiv2021

Axial Anomaly in Galaxies and the Dark Universe

Motivated by the SU(2)$_{\rm CMB}$ modification of the cosmological model $Λ$CDM, we consider isolated fuzzy-dark-matter lumps, made of ultralight axion particles whose masses arise due to distinct SU(2) Yang-Mills scales and the Planck mass $M_P$. In contrast to SU(2)$_{\rm CMB}$, these Yang-Mills theories are in confining phases (zero temperature) throughout most of the Universe's history and associate with the three lepton flavours of the Standard Model of particle physics. As the Universe expands, axionic fuzzy dark matter comprises a three-component fluid which undergoes certain depercolation transitions when dark energy (a global axion condensate) is converted into dark matter. We extract the lightest axion mass $m_{a,e}= 0.675\times 10^{-23}\,$eV from well motivated model fits to observed rotation curves in low-surface-brightness galaxies (SPARC catalogue). Since the virial mass of an isolated lump solely depends on $M_P$ and the associated Yang-Mills scale the properties of an e-lump predict those of $μ$- and $τ$-lumps. As a result, a typical e-lump virial mass $\sim 6.3\times 10^{10}\,M_\odot$ suggests that massive compact objects in galactic centers such as Sagittarius A$^*$ in the Milky Way are (merged) $μ$- and $τ$-lumps. In addition, $τ$-lumps may constitute globular clusters. SU(2)$_{\rm CMB}$ is always thermalised, and its axion condensate never has depercolated. If the axial anomaly indeed would link leptons with dark matter and the CMB with dark energy then this would demystify the dark Universe through a firmly established feature of particle physics.

hep-ph↗