54 research outputs found
Classical glueballs in non-Abelian Born-Infeld theory
It is shown that the Born-Infeld-type modification of the quadratic
Yang-Mills action suggested by the superstring theory gives rise to classical
particle-like solutions prohibited in the standard Yang-Mills theory. This
becomes possible due to the scale invariance breaking by the Born-Infeld
non-linearity. New classical glueballs are sphaleronic in nature and exhibit a
striking similarity with the Bartnik-McKinnon solutions of the Yang-Mills
theory coupled to gravity.Comment: Revtex, 4 pages, 2 eps figure
Perturbative analysis of generalized Einstein's theories
The hypothesis that the energy-momentum tensor of ordinary matter is not
conserved separately, leads to a non-adiabatic expansion and, in many cases, to
an Universe older than usual. This may provide a solution for the entropy and
age problems of the Standard Cosmological Model. We consider two different
theories of this type, and we perform a perturbative analysis, leading to
analytical expressions for the evolution of gravitational waves, rotational
modes and density perturbations. One of these theories exhibits satisfactory
properties at this level, while the other one should be discarded.Comment: 14 pages, Latex fil
Spacetime Symmetries and Z_3-graded Quark Algebra
We investigate certain -graded associative algebras with cubic
-invariant constitutive relations. The invariant forms on finite algebras
of this type are given in the low dimensional cases with two or three
generators.
We show how the Lorentz symmetry represented by the group
emerges naturally without any notion of Minkowskian metric, just as the
invariance group of the -graded cubic algebra and its constitutive
relations. Its representation is found in terms of Pauli matrices. The
relationship of this construction with the operators defining quark states is
also considered, and a third-order analogue of the Klein-Gordon equation is
introduced. Cubic products of its solutions may provide the basis for the
familiar wave functions satisfying Dirac and Klein-Gordon equations.Comment: 15 pages; To appear in the Proceedings of the conference "Quantum
Theory and Symmetries" held in August 2011 in Pragu
Cherenkov radiation in a gravitational wave background
A covariant criterion for the Cherenkov radiation emission in the field of a
non-linear gravitational wave is considered in the framework of exact
integrable models of particle dynamics and electromagnetic wave propagation. It
is shown that vacuum interacting with curvature can give rise to Cherenkov
radiation. The conically shaped spatial distribution of radiation is derived
and its basic properties are discussed.Comment: LaTeX file, no figures, 19 page
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
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