4,309 research outputs found
On the induction of the four-dimensional Lorentz-breaking non-Abelian Chern-Simons action
A four-dimensional Lorentz-breaking non-Abelian Chern-Simons like action is
generated as a one-loop perturbative correction via an appropriate
Lorentz-breaking coupling of the non-Abelian gauge field to the spinor field.
This term is shown to be regularization dependent but nevertheless it can be
found unambiguously in different regularization schemes at zero and finite
temperature.Comment: accepted version in Physical Review
On the aether-like Lorentz-breaking actions
We demonstrate the generation of the CPT-even, aether-like Lorentz-breaking
actions for the scalar and electromagnetic fields via their appropriate
Lorentz-breaking coupling to spinor fields in three, four and five space-time
dimensions. Besides, we show that the aether-like terms for the spinor field
also can be generated as a consequence of the same couplings. Also we discuss
the dispersion relations in the theories with aether-like Lorentz-breaking
terms and find the tree-level effective (Breit) potential for fermion
scattering and the one-loop effective potential corresponding to the action of
the scalar field.Comment: 18 pages, version accepted to Physical Review
Cosmology in the Universe with distance dependent Lorentz-violating bakground
We consider a cosmological setup with the inflaton field in the presence of a
redshift dependent Lorentz-violating time-like background to address the
inflationary regime and other phases of the Universe. We also show that the
regime of dark energy at large distances (low redshifts) is essentially
dominated by the presence of the Lorentz-violating background.Comment: 8 pages, no figure, Latex, to appear in AHE
Mitochondria, telomeres and cell senescence: Implications for lung ageing and disease
Cellular senescence, the irreversible loss of replicative capacity in somatic cells, plays a causal role in the development of age-related pathology and in a number of age-related chronic inflammatory diseases. The ageing lung is marked by an increasing number of senescent cells, and evidence is mounting that senescence may directly contribute to a number of age-related respiratory diseases, including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Telomere dysfunction and alterations in mitochondrial homeostasis frequently occur in cellular senescence and are important to the development of the often detrimental senescence-associated secretory phenotype (SASP). The roles of telomeres, the mitochondria and cellular senescence in lung ageing and disease are discussed. Therapeutic interventions targeting cellular senescence are considered for delaying or potentially reversing age-related respiratory disease
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