8,918 research outputs found
Rivalry in International Relations: A Mimetic Approach to the Case of the Rivalry in Northern Ireland (1963-2020)
This PhD dissertation explores how rivalry, understood as a protracted intractable conflict, emerges, and develops. It takes issue with current approaches to rivalry in International Relations (IR) and Peace and Conflict Studies (P&CS) to advance an alternative, innovative, and interdisciplinary Mimetic Rivalry Framework (MRF) that draws on René Girard’s Mimetic Theory. In contrast to existing research on rivalry in IR and P&CS, the MRF argues for the distinctive nature of rivalry vis-à vis other forms of conflict. It challenges several common assumptions – such as the rationalist assumption on human agency, the materialist assumption on rivalry emergence, and the reification of identity as a difference marker – while embracing complexity, relationality, and mimeticism. Informed by several multi-disciplinary theories – namely, Clyde Kluckhohn’s Social Value Theory, Gabriel Tarde’s Theory of Value, and Leon Festinger’s Social-Comparison Theory – the MRF offers a set of indicators able to empirically trace the stages leading an inter-group dyad from a state of non-competition to the stage of rivalry emergence and, finally, to a full-fledged rivalry. To test the empirical robustness of the framework, the thesis then investigates the rivalry between Republicans/Nationalists/Catholics and Loyalists/Unionists/Protestants in Northern Ireland as it developed around two intractable issues: that of territory (1964-1998), and that of language (1998-2020). In contrast to the existing literature, the MRF shows that the atypical intractability of the Northern Ireland rivalry is a product of the extreme similarity of desires, rather than of their difference. Because intractable difference is an artefact of mimetic rivalry, this dissertation argues that the politics in Northern Ireland remains prone to rivalry’s chronic intractability unless the underlying mimetic matrix of mutually exclusive identities is unveiled and challenged. Finally, the thesis suggests that recent developments in communal relations in the Irish language community indicate that the Irish language has the potential for enabling communal reconciliation
Photospheric activity, rotation, and star-planet interaction of the planet-hosting star CoRoT-6
The CoRoT satellite has recently discovered a hot Jupiter that transits
across the disc of a F9V star called CoRoT-6 with a period of 8.886 days. We
model the photospheric activity of the star and use the maps of the active
regions to study stellar differential rotation and the star-planet interaction.
We apply a maximum entropy spot model to fit the optical modulation as observed
by CoRoT during a uninterrupted interval of about 140 days. Photospheric active
regions are assumed to consist of spots and faculae in a fixed proportion with
solar-like contrasts. Individual active regions have lifetimes up to 30-40
days. Most of them form and decay within five active longitudes whose different
migration rates are attributed to the stellar differential rotation for which a
lower limit of \Delta \Omega / \Omega = 0.12 \pm 0.02 is obtained. Several
active regions show a maximum of activity at a longitude lagging the
subplanetary point by about 200 degrees with the probability of a chance
occurrence being smaller than 1 percent. Our spot modelling indicates that the
photospheric activity of CoRoT-6 could be partially modulated by some kind of
star-planet magnetic interaction, while an interaction related to tides is
highly unlikely because of the weakness of the tidal force.Comment: 9 pages, 7 figures, accepted to Astronomy & Astrophysic
Event generator to construct cross sections for the multiphonon excitation of a set of collective vibrational modes
The construction of differential cross sections as a function of excitation
energy for systems with a collection of low- and high-lying intrinsic
vibrational modes has been attempted in the past. A prescription is proposed
that simplifies the implementation of such calculation schemes with a
remarkable reduction in computational time.Comment: 6 pages, 3 figures, to be published in Phys. Rev.
Mimetic rivalry in practice: The case of Kosovo
In this article, we advance a framework that highlights the relational nature of rivalry emergence and its ongoing manifestations, before illustrating this framework in practice through an analysis of the rivalry between Serbs and Albanians over the issue of Kosovo. We argue that the locus of rivalry lies in the inherently social character of human desire and the destructive reciprocity elicited by human mimetic behaviour. The manner in which rivals portray their plight, and legitimise their cause, is, we argue, a function of their desire to acquire that which they imagine the other has. As such, rather than adhering to the conventional view that rivalries are characterised by difference, we argue that rivals share a set of common goals/desires. Thus, though rivalries are characterised by mutual antipathy – and the attendant devotion to constructing self-serving myths – this is but a superficial manifestation of an underlying mimetic dynamic. To focus only on how myths are constructed and instrumentally employed, is not sufficient when seeking to explain the persistence of rivalries. Rather, we must understand the underlying desires the respective rivals seek to fulfill through the proliferation of these myths if we are to truly understand the nature of the rivalry
Photospheric activity, rotation and magnetic interaction in LHS 6343 A
Context. The Kepler mission has recently discovered a brown dwarf companion
transiting one member of the M4V+M5V visual binary system LHS 6343 AB with an
orbital period of 12.71 days. Aims. The particular interest of this transiting
system lies in the synchronicity between the transits of the brown dwarf C
component and the main modulation observed in the light curve, which is assumed
to be caused by rotating starspots on the A component. We model the activity of
this star by deriving maps of the active regions that allow us to study stellar
rotation and the possible interaction with the brown dwarf companion. Methods.
An average transit profile was derived, and the photometric perturbations due
to spots occulted during transits are removed to derive more precise transit
parameters. We applied a maximum entropy spot model to fit the out-of-transit
optical modulation as observed by Kepler during an uninterrupted interval of
500 days. It assumes that stellar active regions consist of cool spots and
bright faculae whose visibility is modulated by stellar rotation. Results.
Thanks to the extended photometric time series, we refine the determination of
the transit parameters and find evidence of spots that are occulted by the
brown dwarf during its transits. The modelling of the out-of-transit light
curve of LHS 6343 A reveals several starspots rotating with a slightly longer
period than the orbital period of the brown dwarf, i.e., 13.13 +- 0.02 days. No
signature attributable to differential rotation is observed. We find evidence
of a persistent active longitude on the M dwarf preceding the sub- companion
point by 100 deg and lasting for at least 500 days. This can be relevant for
understanding how magnetic interaction works in low-mass binary and star-planet
systems.Comment: 14 pages, 16 figure
Activity cycles in members of young loose stellar associations
Magnetic cycles have been detected in tens of solar-like stars. The
relationship between the cycle properties and global stellar parameters is not
fully understood yet.
We searched for activity cycles in 90 solar-like stars with ages between 4
and 95 Myr aiming to investigate the properties of activity cycles in this age
range.
We measured the length of a given cycle by analyzing the long-term
time-series of three activity indexes. For each star, we computed also the
global magnetic activity index that is proportional to the amplitude of
the rotational modulation and is a proxy of the mean level of the surface
magnetic activity. We detected activity cycles in 67 stars. Secondary cycles
were also detected in 32 stars. The lack of correlation between and
suggest that these stars belong to the Transitional Branch and that
the dynamo acting in these stars is different from the solar one. This
statement is also supported by the analysis of the butterfly diagrams.
We computed the Spearman correlation coefficient between ,
and different stellar parameters. We found that is
uncorrelated with all the investigated parameters. The index is
positively correlated with the convective turn-over time-scale, the magnetic
diffusivity time-scale , and the dynamo number , whereas
it is anti-correlated with the effective temperature , the
photometric shear and the radius at which
the convective zone is located.
We found that is about constant and that decreases with the
stellare age in the range 4-95 Myr. We investigated the magnetic activity of AB
Dor A by merging ASAS time-series with previous long-term photometric data. We
estimated the length of the AB Dor A primary cycle as .Comment: 19 pages , 15 figures, accepte
Determination of rotation periods in solar-like stars with irregular sampling: the Gaia case
We present a study on the determination of rotation periods (P) of solar-like
stars from the photometric irregular time-sampling of the ESA Gaia mission,
currently scheduled for launch in 2013, taking into account its dependence on
ecliptic coordinates. We examine the case of solar-twins as well as thousands
of synthetic time-series of solar-like stars rotating faster than the Sun. In
the case of solar twins we assume that the Gaia unfiltered photometric passband
G will mimic the variability of the total solar irradiance (TSI) as measured by
the VIRGO experiment. For stars rotating faster than the Sun, light-curves are
simulated using synthetic spectra for the quiet atmosphere, the spots, and the
faculae combined by applying semi-empirical relationships relating the level of
photospheric magnetic activity to the stellar rotation and the Gaia
instrumental response. The capabilities of the Deeming, Lomb-Scargle, and Phase
Dispersion Minimisation methods in recovering the correct rotation periods are
tested and compared. The false alarm probability (FAP) is computed using Monte
Carlo simulations and compared with analytical formulae. The Gaia scanning law
makes the rate of correct detection of rotation periods strongly dependent on
the ecliptic latitude (beta). We find that for P ~ 1 d, the rate of correct
detection increases with ecliptic latitude from 20-30 per cent at beta ~
0{\deg} to a peak of 70 per cent at beta=45{\deg}, then it abruptly falls below
10 per cent at beta > 45{\deg}. For P > 5 d, the rate of correct detection is
quite low and for solar twins is only 5 per cent on average.Comment: 12 pages, 18 figures, accepted by MNRA
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