Primordial magnetic field and density fluctuation from early universe phase transition

1991 ◽  
Author(s):  
Jin Wang
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Early Universe ◽  
Density Fluctuation ◽  
Primordial Magnetic Field

EFFECTS OF PRIMORDIAL MAGNETIC FIELD ON EARLY UNIVERSE

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1695-1706 ◽  
Author(s):  
DAI G. YAMAZAKI ◽  
KIYOTOMO ICHIKI ◽  
KAJINO TOSHITAKA ◽  
GRANT J. MATHEWS
Keyword(s):  
Magnetic Field ◽  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Early Universe ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Microwave Background ◽  
Primordial Magnetic Field

The existence of a primordial magnetic field (PMF) would affect both the temperature and polarization anisotropies of the cosmic microwave background (CMB) and the formation of the large scale structure(LSS). It also provides a plausible explanation for the disparity between observations and theoretical fits to the CMB power spectrum and the LSS. Here we report on calculations of not only the numerical power spectrum of the PMF, but also the correlations between the PMF power spectrum and the primary curvature perturbations.

scholarly journals Axion strings are superconducting

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Hajime Fukuda ◽  
Aneesh V. Manohar ◽  
Hitoshi Murayama ◽  
Ofri Telem
Keyword(s):  
Magnetic Field ◽  
Charge Density ◽  
Electric Current ◽  
Early Universe ◽  
Drag Force ◽  
Parameter Space ◽  
Electromagnetic Force ◽  
Large Current ◽  
Primordial Magnetic Field ◽  
Relic Abundance

Abstract We explore the cosmological consequences of the superconductivity of QCD axion strings. Axion strings can support a sizeable chiral electric current and charge density, which alters their early universe dynamics. We examine the possibility that shrinking axion string loops can become effectively stable remnants called vortons, supported by the repulsive electromagnetic force of the string current. We find that vortons in our scenario are generically unstable, and so do not pose a cosmological difficulty. Furthermore, if a primordial magnetic field (PMF) exists in the early universe, a large current is induced on axion strings, creating a significant drag force from interactions with the surrounding plasma. As a result, the strings are slowed down, which leads to an orders of magnitude enhancement in the number of strings per Hubble volume. Finally, we study potential implications for the QCD axion relic abundance. The QCD axion window is shifted by orders of magnitude in some parts of our parameter space.

scholarly journals EDGES signal in the presence of magnetic fields

2020 ◽  
Vol 497 (1) ◽  
pp. L35-L39 ◽  
Author(s):  
Pravin Kumar Natwariya ◽  
Jitesh R Bhatt
Keyword(s):  
Magnetic Field ◽  
Dark Matter ◽  
Magnetic Fields ◽  
Early Universe ◽  
High Energy ◽  
New Physics ◽  
Gas Temperature ◽  
Primordial Magnetic Field ◽  
Energy Processes ◽  
Lower Limits

ABSTRACT We study the 21-cm differential brightness temperature in the presence of primordial helical magnetic fields for redshift z = 10–30. We argue that the α-effect that sets in at earlier time can be helpful in lowering the gas temperature to 3.2 K at z = 17. This effect can arise in the early Universe due to some parity-violating high-energy processes. Using the EDGES (Experiment to Detect the Global Epoch of Reionization Signature) results, we find the upper and lower limits on the primordial magnetic field to be 6 × 10−3 and 5 × 10−4 nG, respectively. We also discuss the effect of Ly α background on the bounds. Our results do not require any new physics in terms of dark matter.

scholarly journals Magnetic-field effects on p-wave phase transition in Gauss–Bonnet gravity

2014 ◽  
Vol 29 (20) ◽  
pp. 1450094 ◽  
Author(s):  
Ya-Bo Wu ◽  
Jun-Wang Lu ◽  
Yong-Yi Jin ◽  
Jian-Bo Lu ◽  
Xue Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
P Wave ◽  
Vector Model ◽  
Magnetic Field Effects ◽  
Complex Vector ◽  
Bonnet Gravity ◽  
Yang Mills ◽  
Wave Phase ◽  
Lowest Landau Level

In the probe limit, we study the holographic p-wave phase transition in the Gauss–Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss–Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang–Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability.

INFLUENCE OF AN EXTERNAL MAGNETIC FIELD ON THE DYNAMICS OF A NEW-PHASE NUCLEUS IN THE VICINITY OF THE FIRST-ORDER PHASE TRANSITION IN MAGNETS WITH DEFECTS PRESENT

2012 ◽  
Vol 26 (28) ◽  
pp. 1250183 ◽  
Author(s):  
VLADIMIR NAZAROV ◽  
RISHAT SHAFEEV
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
External Magnetic Field ◽  
Magnetic Anisotropy ◽  
Spin Reorientation ◽  
Critical Fields ◽  
First Order ◽  
Phase Nucleus ◽  
First Order Phase Transition ◽  
New Phase

Theoretically, with the aid of a soliton model, the evolution of a new-phase nucleus near the first-order spin-reorientation phase transition in magnets has been investigated in an external magnetic field. The influence of an external field and one-dimensional defects of magnetic anisotropy on the dynamics of such nucleus has been demonstrated. The conditions for the localization of the new-phase nucleus in the region of the magnetic anisotropy defect and for its escape from the defect have been determined. The values of the critical fields which bring about the sample magnetization reversal have been identified and estimated.

scholarly journals Magnetic-field induced quantum phase transition and critical behavior in a gapped spin system

2007 ◽  
Vol 310 (2) ◽  
pp. 1352-1354 ◽  
Author(s):  
F. Yamada ◽  
T. Ono ◽  
M. Fujisawa ◽  
H. Tanaka ◽  
T. Sakakibara
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Quantum Phase Transition ◽  
Spin System ◽  
Critical Behavior ◽  
Quantum Phase

scholarly journals Probing the reheating phase through primordial magnetic field and CMB

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Md Riajul Haque ◽  
Debaprasad Maity ◽  
Sourav Pal
Keyword(s):  
Magnetic Field ◽  
Primordial Magnetic Field

scholarly journals Primordial magnetic field limits from cosmological data

2010 ◽  
Vol 82 (8) ◽  
Author(s):  
Tina Kahniashvili ◽  
Alexander G. Tevzadze ◽  
Shiv K. Sethi ◽  
Kanhaiya Pandey ◽  
Bharat Ratra
Keyword(s):  
Magnetic Field ◽  
Cosmological Data ◽  
Primordial Magnetic Field
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