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Non-collinear spin states with unique rotational sense, such as chiral spin-spirals, are recently heavily investigated because of advantages for future applications in spintronics and information technology and as potential hosts for…

We study a novel class of nonsingular time-symmetric cosmological bounces. In this class of four dimensional models the bounce is induced by a perfect fluid with a negative energy density. Metric perturbations are solved in an analytic way…

High Energy Physics - Theory · Physics 2009-11-10 Fabio Finelli

We show that spontaneous density segregation in dense systems of aligning circle swimmers is a condensation phenomenon at odds with the phase separation scenarios usually observed in two-dimensional active matter. The condensates, which…

Soft Condensed Matter · Physics 2024-12-20 Yujia Wang , Bruno Ventéjou , Hugues Chaté , Xia-qing Shi

We investigate the bounce cosmology induced by inhomogeneous viscous fluids in FRW space-time (non necessarly flat), taking into account the early-time acceleration after the bounce. Different forms for the scale factor and several examples…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani

Spin-orbit coupling (SOC) in solids normally originates from the electron motion in the electric field of the crystal. It is key to understanding a variety of spin-transport and topological phenomena, such as Majorana fermions and recently…

Quantum Gases · Physics 2014-11-18 Sergey V. Syzranov , Michael L. Wall , Victor Gurarie , Ana Maria Rey

We introduce a string-inspired model for a bouncing/cyclic universe, utilizing the scalar-tachyon coupling as well as contribution from curvature in a closed universe. The universe undergoes the locked inflation, tachyon matter dominated…

General Relativity and Quantum Cosmology · Physics 2014-01-22 Changhong Li , Lingfei Wang , Yeuk-Kwan E. Cheung

We propose a new cosmological paradigm in which our observed expanding phase is originated from an initially large contracting Universe that subsequently experienced a bounce. This category of models, being geodesically complete, is…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Patrick Peter , Nelson Pinto-Neto

A nonsingular emergent universe cosmology can be realized by a nonconventional spinor field as first developed in \cite{Cai:2012yf}. We study the mechanisms of generating scale-invariant primordial power spectrum of curvature perturbation…

High Energy Physics - Theory · Physics 2014-03-11 Yi-Fu Cai , Youping Wan , Xinmin Zhang

We consider the chiral condensate in the baryonic dense medium using the generalized Sakai-Sugimoto model. It is defined as the vacuum expectation value of open Wilson line that is proposed to be calculated by use of the area of world-sheet…

High Energy Physics - Theory · Physics 2013-04-30 Shigenori Seki , Sang-Jin Sin

We perform a detailed investigation of the simplest possible cosmological model in which a bounce can occur, namely that where the dynamics is led by a simple massive scalar field in a general self-interacting potential and a background…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Felipe T. Falciano , Marc Lilley , Patrick Peter

The quantum action generated by fermions which are minimally coupled to abelian vortex background fields is studied in D=2+1 and D=3+1 Euclidean dimensions. We present a detailed analysis of single- and binary-vortex configurations using…

High Energy Physics - Theory · Physics 2009-11-07 Kurt Langfeld , Laurent Moyaerts , Holger Gies

We discuss how inflation can emerge from a four-fermion interaction induced by torsion. Inflation can arise from coupling torsion to Standard Model fermions, without any need of introducing new scalar particles beyond the Standard Model.…

General Relativity and Quantum Cosmology · Physics 2019-03-12 Andrea Addazi , Pisin Chen , Antonino Marciano

A possibility of a pseudovector-type quark-antiquark condensed phase, which leads to a quark spin polarized phase, in the quark matter is investigated taking account of the vacuum effects leading to the chiral symmetry breaking by using the…

High Energy Physics - Phenomenology · Physics 2023-10-18 Kentaro Hayashi , Yasuhiko Tsue

A nonlinear sigma model is derived for the time development of a Bose-Einstein condensate composed of fermionic atoms. Spontaneous symmetry breaking of a Sp(2) symmetry in a coherent state path integral with anticommuting fields yields…

Statistical Mechanics · Physics 2009-11-11 Bernhard Mieck

We show that the nonlocal two-flavor Nambu--Jona-Lasinio model predicts the enhancement of both chiral and axial symmetry breaking as the chiral imbalance of hot QCD matter, regulated by a chiral chemical potential $\mu_5$, increases. The…

High Energy Physics - Phenomenology · Physics 2020-07-22 Marco Ruggieri , Maxim N. Chernodub , Zhen-Yan Lu

The gravitational effect on the chiral phase structure at finite temperature and density is investigated in the framework of Nambu--Jona-Lasinio model in $D$-dimensional ultrastatic Einstein universe. In mean field approximation, the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Xuguang Huang , Xuewen Hao , Pengfei Zhuang

Many popular models of fractionalized spin liquids contain neutral fermionic spinon excitations on a Fermi surface, carrying unit charges under a compact U(1) gauge force. We argue that instanton effects generically render such states…

Strongly Correlated Electrons · Physics 2011-08-08 Igor F. Herbut , Babak H. Seradjeh , Subir Sachdev , Ganpathy Murthy

For bouncing cosmologies such as the ekpyrotic/cyclic scenarios we show that it is possible to make predictions for density perturbations which are independent of the details of the bouncing phase. This can be achieved, as in inflationary…

High Energy Physics - Theory · Physics 2009-11-10 Paolo Creminelli , Alberto Nicolis , Matias Zaldarriaga

A mechanism for suppressing the cosmological constant is described, using a superconducting analogy in which fermions coupled to gravitons are in an unstable false vauum. The coupling of the fermions to gravitons and a screened attractive…

High Energy Physics - Theory · Physics 2009-11-10 J. W. Moffat

Strongly correlated materials with strong spin-orbit coupling hold promise for realizing topological phases with fractionalized excitations. Here we propose a chiral spin-orbital liquid as a stable phase of a realistic model for…

Strongly Correlated Electrons · Physics 2016-07-04 W. M. H. Natori , E. C. Andrade , E. Miranda , R. G. Pereira