Perturbative quantum gravity in the framework of the Schwinger–Keldysh formalism is applied to compute lowest-order corrections to expansion of the Universe described in terms of the spatially flat Friedman–Lemaître–Robe ...

It has been shown that anisotropy of homogeneous spacetime described by the general Kasner metric can be damped by quantum fluctuations coming from perturbative quantum gravity in one-loop approximation. Also, a formal ...

It is demonstrated that the Pais–Uhlenbeck oscillator in arbitrary dimension enjoys the l -conformal Newton–Hooke symmetry provided frequencies of oscillation form the arithmetic sequence ωk=(2k−1)ω1, where k=1,…,n, and ...

The higher-derivative theories with degenerate frequencies exhibit BRST symmetry [V.O. Rivelles, Phys. Lett. B 577 (2003) 147]. In the present Letter meaning of BRST-invariance condition is analyzed. The BRST symmetry is ...

We report hints for the correlation between the X-ray and gamma-ray emission in the nearby galaxy NGC 4945, which harbors both an active galactic nucleus and a nuclear starburst region. We have divided the Fermi/LAT ...

We report the correlation between the X-ray and γ-ray emission found in our analysis of the Fermi/LAT and Swift/BAT data from 8 years of observations of the nearby Seyfert 2 galaxy NGC 4945. Using the BAT light-curves we ...

The coadjoint orbit method is applied to the construction of Hamiltonian dynamics of massless particles of arbitrary helicity. The unusual transformation properties of canonical variables are interpreted in terms of nonlinear ...

We construct the set of theories which share the property that the tree-level threshold amplitudes nullify even if both initial and final states contain the same type of particles. The origin of this phenomenon lies in ...

Archimedean triangular operators form the basis of the tools for development, analysis and designing of fuzzy systems. They are generated by simple, monotone, single-valued and continuous functions. The basic sets of ...

A rapid amplification of algal population has a negative impact on the environment and the global economy. Thus, control of algal proliferation is an important issue and effective procedures which reduce algal blooms and ...