In the present work, we study the cosmological model with fermionic field and with the non-canonical kinetic term (f-essence). We also present some important reductions of the model as well as its some generalizations. We also found the exact solution of the model and examine the influence of such gravity-fermion interaction on the observed accelerated expansion of our universe. Several fermionic and bosonic-fermionic DBI models were constructed as some particular reductions of f-essence and g-essence, respectively and their Chaplygin gas counterparts are found. Finally, some nonlinear models of bouncing and cyclic universes are proposed.
Is Phantom Divide Crossing in General Relativity Completely Impossible? Shortcomings in canonical and minimally coupled scalar field and Possible Solutions in $k$-essence Models
High Energy Accelerator Research Organization (KEK)(高能加速器研究机构);Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University(名古屋大学小林-益川粒子宇宙起源研究所);ICREA(加泰罗尼亚高级研究中心);Institute of Space Sciences (IEEC-CSIC)(空间科学研究所);Institut d’Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究学院);Aristotle University of Thessaloniki(塞萨洛尼基亚里士多德大学);Khazar University(哈扎尔大学)
Non-Existence of Black Holes with Non-Canonical Scalar Fields
研究了以非正则标量场为物质源的稳态黑洞的存在性。我们证明了一个简单的黑洞无毛定理,它排除了存在的渐近平坦的黑洞是静态的或静止的,轴对称的具有标量头发的广泛的一类非正则标量场理论。这适用于K-本质理论形式的标量场理论。特别是,我们排除了这种黑洞在幽灵凝聚模型中的存在,并在大部门的Dirac Born Infeld模型。
Dynamical System of Scalar Field from 2-Dimension to 3-D and its Cosmological Implication
我们对大多数流行的标量场暗能量模型,包括(幻影)quintessence,(幻影)tachyon,k-essence和一般的非正则标量场模型,给出了三维动力学自治系统,将动力学变量从变量$(x, y, λ)$变为可观测的相关变量$(w_ϕ, Ω_ϕ, λ)$,并展示了k-本质三维系统可还原为(幻影)快子的那些标量场之间的密切关系,一般的非正则标量场可以归约为(幻影)quintessence,k-本质在某些特殊情况下也可以归约为(幻影)quintessence。对于三维动力系统的应用,我们研究了几种特殊情况,并给出了详细的精确动力学解。本文最后指出,用$(w_ϕ, Ω_ϕ, λ)$代替变量$(x, y, λ)$来表示动力系统的微分方程,用三维来研究动力系统比用二维来研究动力系统更方便,也更有物理意义。我们还提出了一个问题,在空间平坦的单标量场FRW宇宙模型中的混沌行为的可能性在普通物质的存在。
From Dark Radiation to Dark Energy: Unified Cosmological Evolution in K-essence Models
Universidad de Guanajuato(瓜纳华托大学);Centro de Investigación y de Estudios Avanzados del I.P.N.(墨西哥国立自治研究所高级研究中心);Secretaría de Ciencia, Humanidades, Tecnología e Innovación(科学、人文、技术与创新秘书处)
Gravitational Wave Propagation in K-essence Cosmology: Theory and Observational Constraints
University of Calcutta(加尔各答大学);Ben-Gurion University of the Negev(内盖夫本-古里安大学);Frankfurt Institute for Advanced Studies (FIAS)(法兰克福高等研究所);Bahamas Advanced Study Institute and Conferences(巴哈马高级研究院与会议);Sister Nivedita University(尼维蒂达修女大学);Pontificia Universidad Católica de Valparaíso(瓦爾帕萊索天主教大學);Prabhat Kumar College(普拉巴特庫瑪學院);Institute of Astronomy, Space and Earth Science(天文、太空與地球科學研究所)