## Search

Now showing items 31-40 of 47

#### Conformal Newton–Hooke symmetry of Pais–Uhlenbeck oscillator

(North-Holland, 2014)

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 ...

#### On the triviality of higher-derivative theories

(North-Holland, 2012)

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 ...

#### Modalities for an Allegorical Conceptual Data Model

(MDPI AG, 2014)

Allegories are enriched categories generalizing a category of sets and binary relations. In this paper, we extend a new, recently-introduced conceptual data model based on allegories by adding support for modal operators ...

#### Weak n-Ary Relational Products in Allegories

(MDPI AG, 2014)

Allegories are enriched categories generalizing a category of sets and binary relations. Accordingly, relational products in an allegory can be viewed as a generalization of Cartesian products. There are several definitions ...

#### The X/gamma-ray correlation in NGC 4945 and the nature of its gamma-ray source

(IOP Publishing for the American Astronomical Society, 2017)

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 ...

#### X-ray/γ-ray Correlation in Seyfert 2 Galaxy NGC 4945

(AIP Conference Proceedings - American Institute of Physics, 2017-01-04)

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 ...

#### Chiral fermions, massless particles and Poincare covariance

(Elsevier, 2015-05-19)

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 ...

#### “Isochronic” dynamical systems and nullification of amplitudes

(North-Holland, 2003)

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 ...

#### Thermal induced structural and magnetic transformations in Fe_{73.5−x}Ce_{x=0,3,5,7}Si_{13.5}B_9Nb_3Cu_1 amorphous alloy

(Springer Netherlands, 2013)

Structural and magnetic properties of amorphous and partly crystallized Fe_{73.5−x}Ce_{x=0,3,5,7}Si_{13.5}B_9Nb_3Cu_1 alloys, were analysed in the temperature ranging from RT to 800 °C with scanning calorimetry and ...

#### Modification of thin films induced by slow heavy ions analysed with PIXE and SRIM

(Springer, 2015-03-17)

In the present work the particle induced X-rays (PIXE) emitted during interaction of inert and active slow heavy (HI) ions with specially prepared thin films were measured. Kinematics of the interaction was simulated ...