DYNAMICAL THEORY OF PHASE TRANSITIONS AND COSMOLOGICAL EW AND QCD PHASE TRANSITIONS

We critically review the cosmological EW and QCD phase transitions. The EW and QCD phase transitions would have proceeded dynamically since the expansion of the universe determines the quench rate and critical behaviors at the onset of phase transition slow down the phase transition. We introduce a real-time quench model for dynamical phase transitions and describe the evolution using a canonical real-time formalism. We find the correlation function, the correlation length and time and then discuss the cosmological implications of dynamical phase transitions on EW and QCD phase transitions in the early universe.

Download Full-text

Dynamical phase transitions and Loschmidt echo in the infinite-range XY model

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2015.0160 ◽

2016 ◽

Vol 374 (2069) ◽

pp. 20150160 ◽

Cited By ~ 36

Author(s):

Bojan Žunkovič ◽

Alessandro Silva ◽

Michele Fabrizio

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Order Parameter ◽

Quantum Systems ◽

Xy Model ◽

Time Behaviour ◽

Dynamical Phase ◽

Dynamical Phase Transitions ◽

Loschmidt Echo ◽

Infinite Range

We compare two different notions of dynamical phase transitions in closed quantum systems. The first is identified through the time-averaged value of the equilibrium-order parameter, whereas the second corresponds to non-analyticities in the time behaviour of the Loschmidt echo. By exactly solving the dynamics of the infinite-range XY model, we show that in this model non-analyticities of the Loschmidt echo are not connected to standard dynamical phase transitions and are not robust against quantum fluctuations. Furthermore, we show that the existence of either of the two dynamical transitions is not necessarily connected to the equilibrium quantum phase transition.

Download Full-text

DYNAMICAL PHASE TRANSITIONS ON COMB LATTICES

Modern Physics Letters B ◽

10.1142/s0217984992001599 ◽

1992 ◽

Vol 06 (29) ◽

pp. 1887-1891

Author(s):

D. CASSI ◽

S. REGINA

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Critical Point ◽

Critical Exponents ◽

Analytical Techniques ◽

Spectral Dimension ◽

Dynamical Phase Transition ◽

Dynamical Phase ◽

Dynamical Phase Transitions ◽

Bethe Lattices

We study by analytical techniques the dynamical phase transition between recursive and transient regime induced on comb lattices by a topological bias. The critical exponents are expressed as functions of the intrinsic dimensions of these structures. In particular we show that, unlike what happens on Bethe lattices, it takes in general two different exponents to characterize the approach to the critical point from the recursive phase and from the transient one. These exponents depend respectively on the connectivity and on the spectral dimension.

Download Full-text