scholarly journals DARK MATTER AND COSMOLOGICAL QCD PHASE TRANSITION

2007 ◽  
Vol 22 (25n28) ◽  
pp. 1971-1985
Author(s):  
W-Y. P. HWANG
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Domain Walls ◽  
Wall Structure ◽  
Complex Scalar ◽  
Latent Energy ◽  
Qcd Phase Transition ◽  
Qcd Vacuum ◽  
Long Run ◽  
Complex Scalar Field

In this talk, we take the wisdom that the cosmological QCD phase transition, which happened at a time between 10−5 sec and 10−4 sec or at the temperature of about 150 MeV and accounts for confinement of quarks and gluons to within hadrons, would be of first order, i.e., would release latent "heat" or latent energy. I wish to base on two important points, i.e. (1) that we have 25% dark matter in the present Universe, and (2) that when the early universe underwent the cosmological QCD phase transition it released 1.02 × 10gm/cm3 in latent energy huge compared to 5.88 × 109 gm/cm3 radiation (photon) energy, to deduce that the two numbers are in fact closely related. It is sufficient to approximate the true QCD vacuum as one of degenerate θ-vacua and can be modelled effectively via a complex scalar field with spontaneous symmetry breaking. We examine how "pasted" or "patched" domain walls are formed, how such walls evolve in the long run, and we believe that the majority of dark matter could be accounted for in terms of such domain-wall structure and its remnants. The latent energy released due to the conversion of the false vacua to the true vacua, in the form of "pasted" or "patched" domain walls at first and their evolved objects, make it obsolete the "radiation-dominated" epoch or later on the "matter-dominated" epoch.

SOME THOUGHTS ON THE COSMOLOGICAL QCD PHASE TRANSITION

2008 ◽  
Vol 23 (30) ◽  
pp. 4757-4777
Author(s):  
W-Y. P. HWANG
Keyword(s):  
Phase Transition ◽  
Scalar Field ◽  
Order Phase Transition ◽  
Domain Walls ◽  
Wall Structure ◽  
Complex Scalar ◽  
Qcd Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

The cosmological QCD phase transitions may have taken place between 10-5 s and 10-4 s in the early universe offers us one of the most intriguing and fascinating questions in cosmology. In bag models, the phase transition is described by the first-order phase transition and the role played by the latent "heat" or energy released in the transition is highly nontrivial and is being classified as the first-order phase transition. In this presentation, we assume, first of all, that the cosmological QCD phase transition, which happened at a time between 10-5 s and 10-4 s or at the temperature of about 150 MeV and accounts for confinement of quarks and gluons to within hadrons, would be of first-order. Of course, we may assume that the cosmological QCD phase transition may not be of the first-order. To get the essence out of the first-order scenario, it is sufficient to approximate the true QCD vacuum as one of possibly degenerate vacua and when necessary we try to model it effectively via a complex scalar field with spontaneous symmetry breaking. On the other hand, we may use a real scalar field in describing the non-first-order QCD phase transition. In the first-order QCD phase transition, we could examine how and when "pasted" or "patched" domain walls are formed, how long such walls evolve in the long run, and we believe that the significant portion of dark matter could be accounted for in terms of such domain-wall structure and its remnants. Of course, the cosmological QCD phase transition happened in the way such that the false vacua associated with baryons and many other color-singlet objects did not disappear (that is, using the bag-model language, there are bags of radius 1.0 fermi for the baryons) — but the amount of the energy remained in the false vacua is negligible by comparison. The latent energy released due to the conversion of the false vacua to the true vacua, in the form of "pasted" or "patched" domain walls in the short run and their numerous evolved objects, should make the concept of the "radiation-dominated" epoch, or of the "matter-dominated" epoch to be reexamined.

scholarly journals PHASE TRANSITIONS, DOMAIN WALLS, AND DARK MATTER

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1055-1062
Author(s):  
W-Y. P. HWANG
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Phase Transitions ◽  
Domain Wall ◽  
Symmetry Breaking ◽  
Early Universe ◽  
Domain Walls ◽  
Chiral Symmetry Breaking ◽  
Complex Scalar ◽  
Qcd Phase Transition

We discuss possible roles in the Early Universe of the electroweak (EW) phase transition, which endows masses to the various particles, and the QCD phase transition, which gives rise to quark confinement and chiral symmetry breaking. Both phase transitions are well-established phenomena in the standard model of particle physics. Presumably, the EW phase transition would have taken place in the early universe at around 10-11sec, or at the temperature of about 300 GeV while QCD phase transition occurred between 10-5sec and 10-4sec, or at about 150 MeV. In this article, I wish to model the EW or QCD phase transition in the early universe as driven by a complex scalar field with spontaneous symmetry breaking such that the continuous degeneracy of the true ground states can be well represented. Specific interest has been directed to nucleation of domains, production of domain walls, and subsequent re-organization of domain walls resulting in "domain-wall nuggets". It is suggested that the domain-wall nuggets contribute to dark matter in the present Universe.

Self-interacting complex scalar field as dark matter

2011 ◽  
Author(s):  
F. Briscese ◽  
Luis Arturo Ureña-López ◽  
Hugo Aurelio Morales-Técotl ◽  
Román Linares-Romero ◽  
Elí Santos-Rodríguez ◽  
...  
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Complex Scalar ◽  
Complex Scalar Field

COMPLEX SCALAR FIELD DARK MATTER

2002 ◽  
pp. 2049-2052
Author(s):  
L. Arturo Ureña-López ◽  
Tonatiuh Matos
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Complex Scalar ◽  
Complex Scalar Field

scholarly journals QUARKS AS TOPOLOGICAL DEFECTS — OR, WHAT IS CONFINED INSIDE A HADRON?

1993 ◽  
Vol 08 (31) ◽  
pp. 5575-5604 ◽  
Author(s):  
A. KOVNER ◽  
B. ROSENSTEIN
Keyword(s):  
Magnetic Flux ◽  
Topological Charge ◽  
Domain Walls ◽  
Topological Defects ◽  
Complex Scalar ◽  
Yang Mills ◽  
Effective Lagrangian ◽  
Local Complex ◽  
Complex Scalar Field ◽  
The One

We present a picture of confinement based on representation of constituent quarks as pointlike topological defects. The topological charge carried by quarks and confined in hadrons is explicitly constructed in terms of Yang-Mills variables. In 2+1 dimensions we are able to construct a local complex scalar field V(x), in terms of which the topological charge is [Formula: see text]. The VEV of the field V in the confining phase is nonzero and the charge is the winding number corresponding to homotopy group π1(S1). Quarks carry the charge Q and therefore are topological solitons. The phase rotation of V is generated by the operator of magnetic flux. Unlike in QED, the U(1) magnetic flux is explicitly broken by the monopoles. This results in formation of a string between a quark and an antiquark. The effective Lagrangian for V is derived in models with adjoint and fundamental quarks. This topological mechanism of confinement is basically different from the one proposed by ’t Hooft in which the elementary objects are linelike domain walls. A baryon is described as a Y-shaped configuration of strings. In 3+1 dimensions the explicit expression for V, and therefore a detailed picture, is not available. However, assuming the validity of the same mechanism we point out several interesting qualitative consequences.

COLOR CONFINEMENT AND FINITE TEMPERATURE QCD PHASE TRANSITION

2004 ◽  
Vol 19 (02) ◽  
pp. 271-285 ◽  
Author(s):  
H. C. PANDEY ◽  
H. C. CHANDOLA ◽  
H. DEHNEN
Keyword(s):  
Phase Transition ◽  
Critical Temperature ◽  
Effective Potential ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Zero Temperature ◽  
Expectation Value ◽  
Qcd Phase Transition ◽  
Qcd Vacuum ◽  
Color Confinement

We study an effective theory of QCD in which the fundamental variables are dual magnetic potentials coupled to the monopole field. Dual dynamics are then used to explain the properties of QCD vacuum at zero temperature as well as at finite temperatures. At zero temperature, the color confinement is realized through the dynamical breaking of magnetic symmetry, which leads to the magnetic condensation of QCD vacuum. The flux tube structure of SU(2) QCD vacuum is investigated by solving the field equations in the low energy regimes of the theory, which guarantees dual superconducting nature of the QCD vacuum. The QCD phase transition at finite temperature is studied by the functional diagrammatic evaluation of the effective potential on the one-loop level. We then obtained analytical expressions for the vacuum expectation value of the condensed monopoles as well as the masses of glueballs from the temperature dependent effective potential. These nonperturbative parameters are also evaluated numerically and used to determine the critical temperature of the QCD phase transition. Finally, it is shown that near the critical temperature (Tc≃0.195 GeV ), continuous reduction of vacuum expectation value (VEV) of the condensed monopoles caused the disappearance of vector and scalar glueball masses, which brings a second order phase transition in pure SU(2) gauge QCD.

scholarly journals COMPLEX SCALAR FIELD DARK MATTER ON GALACTIC SCALES

2014 ◽  
Vol 29 (02) ◽  
pp. 1430002 ◽  
Author(s):  
TANJA RINDLER-DALLER ◽  
PAUL R. SHAPIRO
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Early Universe ◽  
Einstein Condensate ◽  
Model Parameters ◽  
Galactic Halos ◽  
Complex Scalar ◽  
Bose Einstein Condensate ◽  
Complex Scalar Field ◽  
Bose Einstein

The nature of the cosmological dark matter (DM) remains elusive. Recent studies have advocated the possibility that DM could be composed of ultra-light, self-interacting bosons, forming a Bose–Einstein condensate (BEC) in the very early Universe. We consider models which are charged under a global U(1)-symmetry such that the DM number is conserved. It can then be described as a classical complex scalar field which evolves in an expanding Universe. We present a brief review on the bounds on the model parameters from cosmological and galactic observations, along with the properties of galactic halos which result from such a DM candidate.

scholarly journals Two-loop beta function for complex scalar electroweak multiplets

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Joachim Brod ◽  
Zachary Polonsky
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Irreducible Representation ◽  
Beta Function ◽  
Higher Order ◽  
Radiative Corrections ◽  
Point Interactions ◽  
Complex Scalar ◽  
Complex Scalar Field ◽  
Higgs Portal

Abstract We present the general form of the renormalizable four-point interactions of a complex scalar field furnishing an irreducible representation of SU(2), and derive a set of algebraic identities that facilitates the calculation of higher-order radiative corrections. As an application, we calculate the two-loop beta function for the SM extended by a scalar multiplet, and provide the result explicitly in terms of the group invariants. Our results include the evolution of the Higgs-portal couplings, as well as scalar “minimal dark matter”. We present numerical results for the two-loop evolution of the various couplings.

scholarly journals Effective Potential Formalism at Finite Temperature in Dual QCD and Deconfilnement Phase Transition

2019 ◽  
Vol 201 ◽  
pp. 09009
Author(s):  
Garima Punetha ◽  
H. C. Chandola
Keyword(s):  
Phase Transition ◽  
Thermal Effects ◽  
Effective Theory ◽  
Qcd Phase Transition ◽  
First Order ◽  
Pure Gauge ◽  
Qcd Vacuum ◽  
Magnetic Symmetry ◽  
Deconfinement Phase Transition ◽  
Potential Formalism

We study the pure-gauge QCD phase transition at filnite temperatures in the dual QCD theory, an effective theory of QCD based on the magnetic symmetry. We formulate the effective thermodynamical potential for filnite temperatures using the path-integral formalism in order to investigate the properties of the pure-gauge QCD vacuum. Thermal effects bring a first-order deconfinement phase transition.

NUCLEON PROPERTIES IN THE EXPANDING UNIVERSE

2003 ◽  
Vol 18 (02n06) ◽  
pp. 374-383
Author(s):  
W-Y. PAUCHY HWANG
Keyword(s):  
Phase Transition ◽  
Early Universe ◽  
Mass Formula ◽  
The State ◽  
Nucleon Mass ◽  
Expanding Universe ◽  
Qcd Phase Transition ◽  
Qcd Vacuum ◽  
The Universe

Our universe expands and cools. The electroweak (EW) phase transition, which endows masses to the various particles, and QCD phase transition, which gives rise to confinement of quarks and gluons within hadrons in the true QCD vacuum, Would presumably have taken place in the early universe, respectively, at around 10-11 sec and at a time between 10-5 sec and 10-4 sec, or at the temperature of about 300 GeV and of about 150 MeV, respectively. It is clear that the nucleon mass [Formula: see text], the axial coupling [Formula: see text], and other nucleon parameters evolve as the universe evolves, thereby serving as an important gauge for understanding the state of the Universe.

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