Kibble mechanism for electroweak magnetic monopoles and magnetic fields

The vacuum manifold of the standard electroweak model is a three-sphere when one considers homogeneous Higgs field configurations. For inhomogeneous configurations we argue that the vacuum manifold is the Hopf fibered three sphere and that this viewpoint leads to general criteria to detect electroweak monopoles and Z-strings. We extend the Kibble mechanism to study the formation of electroweak monopoles and strings during electroweak symmetry breaking. The distribution of magnetic monopoles produces magnetic fields that have a spectrum Bλ ∝ λ−2, where λ is a smearing length scale. Even as the magnetic monopoles annihilate due to the confining Z-strings, the magnetic field evolves with the turbulent plasma and may be relevant for cosmological observations.

Observational scalings testing modified gravity

We consider different observational effects to test a modified gravity approach involving the cosmological constant in the common description of dark matter and dark energy.We obtain upper limits for the cosmological constant by studying the scaling relations for 12 nearby galaxy clusters, the radiated power from gravitational waves and the Tully-Fisher relation for super spiral galaxies. Our estimations reveal that, for all these cases, the upper limits for Λ are consistent with its actual value predicted by cosmological observations.

Dark matter halo with charge in pseudo-spheroidal geometry

The concept of dark matter (DM) hypothesis comes out as a result from the input of the observed flat rotational velocity. With the assumption that the galactic halo is pseudo-spheroidal and filled with charged perfect fluid, we have obtained a solution which has inkling to a (nearly) flat universe, compatible with the modern day cosmological observations. Various other important aspects of the solution such as attractive gravity in the halo region and the stability of the circular orbit are also explored. Also, the matter in the halo region satisfies the known equation of state which indicates its non-exotic nature.

Anisotropic Bianchi type-II modified holographic Ricci dark energy model in scale-covariant theory of gravitation

In this paper, we obtain an anisotropic Bianchi type-II space-time with dark matter and the modified holographic Ricci dark energy in the scale-covariant theory of gravitation. Exact solutions of the field equations are obtained by assuming (I) a negative constant value of the deceleration parameter (II) the component σ¹₁ of the shear tensor σ^j_i is proportional to the mean Hubble parameter and (III) the gauge function Φ is proportional to a power function of the average scale factor. We have also discussed some important physical aspects of the model which is in agreement with the modern cosmological observations.

A new way to test the WIMP dark matter models

In this paper, we investigate the possibility of testing the weakly interacting massive particle (WIMP) dark matter (DM) models by applying the simplest phenomenological model which introduces an interaction term between dark energy (DE) and WIMP DM, i.e., Q = 3γDMHρDM. In general, the coupling strength γDE is close to 0 as the interaction between DE and WIMP DM is very weak, thus the effect of γDE on the evolution of Y associated with DM energy density can be safely neglected. Meanwhile, our numerical calculation also indicates that xf ≈ 20 is associated with DM freeze-out temperature, which is the same as the vanishing interaction scenario. As for DM relic density, it will be magnified by $$ \frac{2-3{\upgamma}_{\mathrm{DM}}}{2}{\left[2\pi {g}_{\ast }{m}_{\mathrm{DM}}^3/\left(45{s}_0{x}_f^3\right)\right]}^{\gamma_{\mathrm{DM}}} $$ 2 − 3 γ DM 2 2 π g ∗ m DM 3 / 45 s 0 x f 3 γ DM times, which provides a new way to test WIMP DM models. As an example, we analyze the case in which WIMP DM is a scalar DM. (SGL+SNe+Hz) and (CMB+BAO+SNe) cosmological observations will give γDM = $$ {0.134}_{-0.069}^{+0.17} $$ 0.134 − 0.069 + 0.17 and γDM = −0.0008 ± 0.0016, respectively. After further considering the constraints from DM direct detection experiment, DM indirect detection experiment, and DM relic density, we find that the allowed parameter space of the scalar DM model will be completely excluded for the former cosmological observations, while it will increase for the latter ones. Those two cosmological observations lead to an almost paradoxical conclusion. Therefore, one could expect more stringent constraints on the WMIP DM models, with the accumulation of more accurate cosmological observations in the near future.

Non-relativistic and potential non-relativistic effective field theories for scalar mediators

Yukawa-type interactions between heavy Dirac fermions and a scalar field are a common ingredient in various extensions of the Standard Model. Despite of that, the non-relativistic limit of the scalar Yukawa theory has not yet been studied in full generality in a rigorous and model-independent way. In this paper we intend to fill this gap by initiating a series of investigations that make use of modern effective field theory (EFT) techniques. In particular, we aim at constructing suitable non-relativistic and potential non-relativistic EFTs of Yukawa interactions (denoted as NRY and pNRY respectively) in close analogy to the well known and phenomenologically successful non-relativistic QCD (NRQCD) and potential non-relativistic QCD (pNRQCD). The phenomenological motivation for our study lies in the possibility to explain the existing cosmological observations by introducing heavy fermionic dark matter particles that interact with each other by exchanging a light scalar mediator. A systematic study of this compelling scenario in the framework of non-relativistic EFTs (NREFTs) constitutes the main novelty of our approach as compared to the existing studies.

The origin of rest-mass energy

Today we have a solid, if incomplete, physical picture of how inertia is created in the standard model. We know that most of the visible baryonic ‘mass’ in the Universe is due to gluonic back-reaction on accelerated quarks, the latter of which attribute their own inertia to a coupling with the Higgs field – a process that elegantly and self-consistently also assigns inertia to several other particles. But we have never had a physically viable explanation for the origin of rest-mass energy, in spite of many attempts at understanding it towards the end of the nineteenth century, culminating with Einstein’s own landmark contribution in his Annus Mirabilis. Here, we introduce to this discussion some of the insights we have garnered from the latest cosmological observations and theoretical modeling to calculate our gravitational binding energy with that portion of the Universe to which we are causally connected, and demonstrate that this energy is indeed equal to $$mc^2$$ m c 2 when the inertia m is viewed as a surrogate for gravitational mass.

Conformal Higgs model: Gauge fields can produce a 125 GeV resonance

Recent cosmological observations and compatible theory offer an understanding of long-mysterious dark matter and dark energy. The postulate of universal conformal local Weyl scaling symmetry, without dark matter, modifies action integrals for both Einstein–Hilbert gravitation and the Higgs scalar field by gravitational terms. Conformal theory accounts for both observed excessive external galactic orbital velocities and for accelerating cosmic expansion. SU(2) symmetry-breaking is retained by the conformal scalar field, which does not produce a massive Higgs boson, requiring an alternative explanation of the observed LHC 125 GeV resonance. Conformal theory is shown here to be compatible with a massive neutral particle or resonance [Formula: see text] at 125 GeV, described as binary scalars [Formula: see text] and [Formula: see text] interacting strongly via quark exchange. Decay modes would be consistent with those observed at LHC. Massless scalar field [Formula: see text] is dressed by the [Formula: see text] field to produce Higgs Lagrangian term [Formula: see text] with the empirical value of [Formula: see text] known from astrophysics.

The Theoretical Value of the Hubble Constant Ho and Unification of the Fundamental Forces of Nature

The Hubble constant Ho represents the speed of expansion of the universe and various cosmological observations and modeling methods were utilized by astronomers for a century to pin down its exact value. Determining Ho from cosmological observations is a long and tedious process requiring highly accurate datasets. To circumvent this need, a simple theoretical approach is introduced in this study which uses the concept of gravitational weakening and seismic-induced recession. As tremors occur among celestial objects, their gravitational fields would also change. This resulted in a fundamental relation of Ho and the computed rate of recession that gives a theoretical value for Ho=69.921 Km/s/Mpc. Using the newly discovered seismic-induced gravitational weakening and time dilation, it is possible that various astrophysical methods using different measurement methods would converge to this theoretical Ho value when cosmological distances and time delay measurements are corrected with the simple formulas we derived. The new model assumes that, as quakes occur in celestial objects, luminosity-induced acceleration and high-energy collision of protons and electrons may produce a massive number of neutrinos, quarks and other subatomic particles. Furthermore, the fine structure constant was found to be inversely proportional to Ho-squared and that the fine-structure constant obtained in this study gives a new physical interpretation of α. New relations for the speed of light, orbital velocity, gravitational force and the Hubble constant were further derived from the new recession constant using approximate relations for the Newtonian and electric force constant. This resulted in a modified gravitational law that is both repulsive and attractive and a theoretical explanation of the phenomenon of light-induced gravitation analogous to the electromagnetic force where photon is the force-carrier. Finally, the fundamental forces of gravitation, electromagnetism and strong nuclear force are now unified.