Orbit classification in the meridional plane of a disk galaxy model with a spherical nucleus

We investigate the regular or chaotic nature of star orbits moving in the meridional plane of an axially symmetric galactic model with a disk and a spherical nucleus. We study the influence of some important parameters of the dynamical system, such as the mass and the scale length of the nucleus, the angular momentum or the energy, by computing in each case the percentage of chaotic orbits, as well as the percentages of orbits of the main regular resonant families. Some heuristic arguments to explain and justify the numerically derived outcomes are also given. Furthermore, we present a new method to find the threshold between chaos and regularity for both Lyapunov Characteristic Numbers and SALI, by using them simultaneously.Comment: Published in Celestial Mechanics & Dynamical Astronomy (CMDA) journa

On a possible origin for the lack of old star clusters in the Small Magellanic Cloud

We model the dynamical interaction between the Small and Large Magellanic Clouds and their corresponding stellar cluster populations. Our goal is to explore whether the lack of old clusters ($\gtrsim 7$ Gyr) in the Small Magellanic Cloud (SMC) can be the result of the capture of clusters by the Large Magellanic Cloud (LMC), as well as their ejection due to the tidal interaction between the two galaxies. For this purpose we perform a suite of numerical simulations probing a wide range of parameters for the orbit of the SMC about the LMC. We find that, for orbital eccentricities $e \geq 0.4$, approximately 15 per cent of the SMC clusters are captured by the LMC. In addition, another 20 to 50 per cent of its clusters are ejected into the intergalactic medium. In general, the clusters lost by the SMC are the less tightly bound cluster population. The final LMC cluster distribution shows a spatial segregation between clusters that originally belonged to the LMC and those that were captured from the SMC. Clusters that originally belonged to the SMC are more likely to be found in the outskirts of the LMC. Within this scenario it is possible to interpret the difference observed between the star field and cluster SMC Age-Metallicity Relationships for ages $\gtrsim 7$ Gyr.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

Orbit classification in the meridional plane of a disk galaxy model with spherical nucleus

We investigate the regular or chaotic nature of star orbits moving in themeridional plane of an axially symmetric galactic model with a disk and a spherical nucleus. We study the influence of some important parameters of the dynamical system, such as the mass and the scale length of the nucleus, the angular momentum or the energy, by computing in each case the percentage of chaotic orbits, as well as the percentages of orbits of the main regular resonant families. Some heuristic arguments to explain and justify the numerically derived outcomes are also given. Furthermore,we present a newmethod to find the threshold between chaos and regularity for both Lyapunov Characteristic Numbers and SALI, by using them simultaneously.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

Upper and lower nearly (i, j)-continuous multifunctions

In this paper the authors introduce and study upper and lower nearly (I,J)-continuous multifunctions. Some characterizations and several properties concerning upper (lower) nearly (I,J)-continuous multifunctions are obtained. The results improves many results in Literature

Orbit classification in the meridional plane of a disk galaxy model with spherical nucleus

We investigate the regular or chaotic nature of star orbits moving in themeridional plane of an axially symmetric galactic model with a disk and a spherical nucleus. We study the influence of some important parameters of the dynamical system, such as the mass and the scale length of the nucleus, the angular momentum or the energy, by computing in each case the percentage of chaotic orbits, as well as the percentages of orbits of the main regular resonant families. Some heuristic arguments to explain and justify the numerically derived outcomes are also given. Furthermore,we present a newmethod to find the threshold between chaos and regularity for both Lyapunov Characteristic Numbers and SALI, by using them simultaneously.Instituto de Astrofísica de La PlataFacultad de Ciencias Astronómicas y Geofísica

A note on preservation of generalized fredholm spectra in berkani’s sense

In this paper, we study the relationships between the spectra derived from B-Fredholm theory corresponding to two given bounded linear operators. The main goal of this paper is to obtain sufficient conditions for which the spectra derived from B-Fredholm theory corresponding to two given operators are respectively the same. Among other results, we prove that B-Fredholm type spectral properties for an operator and its restriction are equivalent, as well as obtain conditions for which B-Fredholm type spectral properties corresponding to two given operators are the same. As application of our results, we obtain conditions for which the above mentioned spectra and the spectra derived from the classical Fredholm theory are the same

Near ω-continuous multifunctions on bitopological spaces

In this paper, we introduce and study basic characterizations, several properties of upper (lower) nearly (i; j)-!-continuous multifunctions on bitopological space

Aroma Fingerprint Characterisation of La Mancha Red Wines

In the present study, Rojal, Moravia Dulce and Tortosí wines were elaborated across four harvests (2006to 2009) from minority red grape varieties cultivated in the La Mancha region of Spain. Wines werestudied by instrumental and sensory analysis to determine the influence of grape variety on the aromaof the wine. Aroma compounds were isolated by solid phase extraction (SPE) to later be analysed usinggas chromatography–mass spectrometry (GC/MS). The odour activity values (OAVs) for the differentcompounds were classified into seven odorant series that describe the aroma profile of these wines (1: fruity,2: floral, 3: green/fresh, 4: sweet, 5: spice, 6: fatty, and 7: other odours). The total intensities of everyaromatic series were calculated as sum of the OAV of each one of the compounds assigned to this series. Allwines showed the same sequence, with the highest aroma contribution being those of the sweet and fruityseries, followed by fatty. The sensory profile of Rojal, Moravia Dulce and Tortosí wines was evaluated byexperienced wine tasters using a non-structured scale. The panellists founded several differences betweentheir sensory profiles. This study provides a complete aromatic characterisation of these wines

On the hereditary character of new strong variations of weyl type theorems

Berkani and Kachad [18], [19], and Sanabria et al. [32], introduced and studied strong variations of Weyl type Theorems. In this paper, we study the behavior of these strong variations of Weyl type theorems for an operator T on a proper closed and Tinvariant subspace W ⊆ X such that T n (X) ⊆ W for some n ≥ 1, where T ∈ L(X) and X is an infinite-dimensional complex Banach space. The main purpose of this paper is to prove that for these subspaces (which generalize the case T n (X) closed for some n ≥ 0), these strong variations of Weyl type theorems are preserved from T to its restriction on W and vice-versa. As consequence of our results, we give sufficient conditions for which these strong variations of Weyl type Theorems are equivalent for two given operators. Also, some applications to multiplication operators acting on the boundary variation space BV [0, 1] are given

Weyl type theorems for restrictions of bounded linear operators

In this paper we give sufficient conditions for which Weyl’s theorems for a bounded linear operator T, acting on a Banach space X, can be reduced to the study of Weyl’s theorems for some restriction of T.peerReviewe