scholarly journals Liquid-gas phase transitions and CK symmetry in quantum field theories

2017 ◽  
Vol 95 (7) ◽  
Author(s):  
Hiromichi Nishimura ◽  
Michael C. Ogilvie ◽  
Kamal Pangeni
Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 403-423 ◽  
Author(s):  
Midya Parto ◽  
Yuzhou G. N. Liu ◽  
Babak Bahari ◽  
Mercedeh Khajavikhan ◽  
Demetrios N. Christodoulides

AbstractIn the past few years, concepts from non-Hermitian (NH) physics, originally developed within the context of quantum field theories, have been successfully deployed over a wide range of physical settings where wave dynamics are known to play a key role. In optics, a special class of NH Hamiltonians – which respects parity-time symmetry – has been intensely pursued along several fronts. What makes this family of systems so intriguing is the prospect of phase transitions and NH singularities that can in turn lead to a plethora of counterintuitive phenomena. Quite recently, these ideas have permeated several other fields of science and technology in a quest to achieve new behaviors and functionalities in nonconservative environments that would have otherwise been impossible in standard Hermitian arrangements. Here, we provide an overview of recent advancements in these emerging fields, with emphasis on photonic NH platforms, exceptional point dynamics, and the very promising interplay between non-Hermiticity and topological physics.


1997 ◽  
Vol 12 (06) ◽  
pp. 1195-1203
Author(s):  
L. C. R. Wijewardhana

Quantum field theories can exist in different phases depending on the number of massless fermion flavors they have. The vacuum structure of such a theory can be changed by varying the flavor number across a critical value. In this lecture we discuss such structure changing phase transitions in three and four dimensional gauge field theories.


2002 ◽  
Vol 16 (04) ◽  
pp. 93-106 ◽  
Author(s):  
ELEONORA ALFINITO ◽  
ORESTE ROMEI ◽  
GIUSEPPE VITIELLO

By resorting to some results in quantum field theories with spontaneous breakdown of symmetry, we show that an explanation based on microscopic dynamics can be given for the fact that topological defect formation is observed during the process of non-equilibrium phase transitions characterized by a non-zero order parameter. We show that the Nambu–Goldstone particle acquires an effective non-zero mass due to boundary (finite volume) effects and this is related to the size of the defect. We also relate such volume effects with temperature effects.


1985 ◽  
Vol 40 (7) ◽  
pp. 752-773
Author(s):  
H. Stumpf

Unified nonlinear spinorfield models are self-regularizing quantum field theories in which all observable (elementary and non-elementary) particles are assumed to be bound states of fermionic preon fields. Due to their large masses the preons themselves are confined and below the threshold of preon production the effective dynamics of the model is only concerned with bound state reactions. In preceding papers a functional energy representation, the statistical interpretation and the dynamical equations were derived and the effective dynamics for preon-antipreon boson states and three preon-fermion states (with corresponding anti-fermions) was studied in the low energy limit. The transformation of the functional energy representation of the spinorfield into composite particle functional operators produced a hierarchy of effective interactions at the composite particle level, the leading terms of which are identical with the functional energy representation of a phenomenological boson-fermion coupling theory. In this paper these calculations are extended into the high energy range. This leads to formfactors for the composite particle interaction terms which are calculated in a rough approximation and which in principle are observable. In addition, the mathematical and physical interpretation of nonlocal quantum field theories and the meaning of the mapping procedure, its relativistic invariance etc. are discussed.


2021 ◽  
Vol 111 (2) ◽  
Author(s):  
Marco Benini ◽  
Marco Perin ◽  
Alexander Schenkel ◽  
Lukas Woike

AbstractThis paper develops a concept of 2-categorical algebraic quantum field theories (2AQFTs) that assign locally presentable linear categories to spacetimes. It is proven that ordinary AQFTs embed as a coreflective full 2-subcategory into the 2-category of 2AQFTs. Examples of 2AQFTs that do not come from ordinary AQFTs via this embedding are constructed by a local gauging construction for finite groups, which admits a physical interpretation in terms of orbifold theories. A categorification of Fredenhagen’s universal algebra is developed and also computed for simple examples of 2AQFTs.


2010 ◽  
Vol 105 (25) ◽  
Author(s):  
Jutho Haegeman ◽  
J. Ignacio Cirac ◽  
Tobias J. Osborne ◽  
Henri Verschelde ◽  
Frank Verstraete

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