The aim of this study is to obtain a better understanding of what factors affect the motivation for visiting Dark Tourism sites and the way that these sites are regarded. By providing such an insight this study contributes to a greater understanding of Dark Tourism.  In order to find answers to our questions, we interviewed several representatives at different sites and also carried out observations at three Dark Tourism attractions to reach a better understanding of the visors’ motivations for visiting this kind of tourist attractions. In our study we have concluded that people have become increasingly interested in visiting such Dark Tourism sites even though these may seem scary or uncomfortable. Our research has helped us to find answers to the questions that we asked and we have concluded that people have become more curious and want to know more about terrible events and why they took place.

The abundance of satellite galaxies is a critical small-scale test of the standard cosmological model. From comparing the predictions of structure formation in simulations with observations of Local Group dwarf galaxies there is a clear mismatch in the abundance, leading to the so-called “missing satellites” problem. The comparison between simulation and observation have, however, suffered from a limited sample of satellite galaxies, with the only reasonably complete sample being from the most local galaxy groups. It is unknown whether the observed abundance of dwarf satellite galaxies of the nearest groups is statistically representative of the abundance of dwarf satellites in the greater universe. We construct a volume-limited sample of galaxies down to a well-defined stellar mass limit (M★ ≥ 6 × 109 Msun ) using the Atlas3D parent sample of spiral and ellipsoidal galaxies by Cappellari et al. 2011. In order to statistically identify bound satellites around galaxies in our primary catalogue, we apply cuts on the background based on the properties of known dwarf satellites of the Local Group using both the Sloan Digital Sky Survey Data Release 8 (SDSS DR8) (http://www.sdss3.org/dr8/) spectroscopic and photometric galaxy catalogues. We detect an over-density of faint objects at projected separations of < 500 kpc at S/N ∼ 8, corresponding to an average of 4.8 ± 0.65 satellite detections per primary after stacking these systems and subtracting the background. We further find that the over-density of faint objects strongly depends on primary morphology and magnitude. While the Milky Way seems to be unusual in its number of bright satellites, our faint end satellite abundances are in agreement from the ∆m luminosity function for primaries in our sample as bright as the Milky Way. Our work has extended the work of previous authors by several magnitudes further down the faint end of the luminosity function.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xix, 302 p. : ill. (some col.). Advisor: David H. Weinberg, Department of Astronomy. Includes bibliographical references (p. 291-302).

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xiv, 86 p.; also includes graphics. Includes bibliographical references (p. 83-86).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xviii, 319 p.; also includes graphics. Includes bibliographical references (p. 310-319). Available online via OhioLINK's ETD Center

We report investigations of physical possibilities beyond the Standard Model, performed in the years between Runs I and II of the Large Hadron Collider (LHC). First, we explore the feasibility of using a hadron collider to unmask hidden sectors by means of a novel signal, the ``monocline". Dilepton production provides the cleanest channel to anticipate a monocline. A compelling sector to seek is dark matter with scalar messengers coupling it to standard fermions. We present current bounds from dilepton spectrum measurements at the LHC and make predictions for sensitivities at Run II of the LHC as well as at a future 100 TeV collider. Second, we corner the space of parameters of supersymmetric frameworks with an appreciable Yukawa coupling between the Higgs fields and a gauge singlet, the so-called Fat Higgs and $\lambda$-SUSY models, in the context of the discovery of the 125 GeV Higgs particle. These models are motivated by their alleviation of the electroweak fine-tuning that supersymmetry breaking entails, via raising the tree-level quartic coupling Higgs boson. Heavy Higgs scalars that couple strongly to the standard Higgs boson induce large radiative corrections to the Higgs quartic coupling, which is crucial to phenomenology; in particular, a very large ratio of the Higgs VEVs ($\tan \beta$), that was previously presumed unfavorable in these models, becomes viable and can be probed by future experiments. In such regions, the most stringent limits come from dark matter constraints on the lightest neutralino. Finally, we place limits on colored scalar production at the LHC in supersymmetric models where gauginos acquire both Dirac and Majorana masses, that we call ``mixed gauginos". While it was known that purely Dirac gluinos were less constrained by LHC searches than their purely Majorana counterparts, we find that the constraints further weaken or strengthen depending on which of the ``mixed" colored fermions acquires a Majorana mass. Also explored are the effects on squark production of turning on Majorana masses for electroweak gauginos. This dissertation consists of previously published and unpublished co-authored material.

Thesis (MTech(Tourism and Hospitality Management))--Cape Peninsula University of Technology, 2011 / Rwanda is a low income, landlocked and heavily populated country in Sub-Sahara Africa. Regardless of its majestic landscape, rich history and culture, it is not a country that is recognized as a tourism destination. Instead, Rwanda has become known for the genocide that took place in 1994 when over one million people were killed in within a hundred day period while the rest of the world watched in silence. Since then, Rwanda has been trying to uplift its image and economy. However, unlike other African countries, Rwanda does not have mineral resources and has to focus on improving its tourism to attract more people and thereby more funds into the country. Developing tourism can play a major role in reducing the poverty level, creating employment as well as contributing to the country’s revenue. So far Rwanda has strongly relied on its famous mountain gorillas to attract tourists which can be an expensive exercise for tourists in Rwanda. By creating a more diversified number of attractions, the number of tourists to the country should increase thereby injecting much needed capital into the economy. After the 1994 genocide, Rwanda inherited several genocide sites that have been preserved by government to remind people of the massacre that took place. Even though these sites are not used for tourism gain, they are acquiring popularity as tourists to Rwanda become aware of them and the history applicable thereto. This study has been undertaken to find ways to conserve, protect and market the genocide memorial sites as tourism destinations. It is important that these heritage museums be acknowledged through the World Heritage Organisation as authentic and educational facilities for future generations to enjoy. The research project was conducted in the Kigali and Bugesera areas. A sample of three hundred and sixty (360) questionnaires was given out to participants, and a total of a hundred and fifty-seven (157) were returned, coded and analysed. Data analysis applying descriptive statistics was utilised to acquire the frequencies, which were conveyed in percentages. The study disclosed that generally tourists were impressed by the genocide memorial sites and felt that it would be of great use to protect and market them as tourism assets as they believe that many people will learn from the harsh historical event that took place in Rwanda. This investigative study could strongly benefit Rwanda in planning and deciding on an appropriate tourism marketing strategy for the genocide memorial site. The Rwandan Government, policy makers and tourism stakeholders have a lot to gain by addressing the issues that are slowing down the tourism industry. It is anticipated that when these barriers have been removed, it will add toward sustainable tourism development in Rwanda.

Although about a century has passed since its discovery, and despite the scientific and technological progress of our society has gone through, the nature of the Dark Matter (DM) is a mystery not yet solved. It is a big challenge for the scientific community, its identification would mean the understanding of what seemingly makes up 84% of the matter content in the Universe. We say “seemingly” because so far all evidences for DM are purely gravitational. This implies that what we call dark matter could be either a manifestation of our incomplete understanding of gravity on large scales, or a new form of matter, in particular a new kind of elementary particle. Among the plethora of possible DM candidates, this work will consider the Weakly Interactive Massive Particle (WIMP). Up to know the observed value for the relic abundance is the only solid parameter which we can count on, and the WIMP is the candidate that, through a fashionable mechanism of production, gives a result for the relic abundance in agreement with the cosmological observations. In order to demonstrate that this is indeed the valid explanation to the DM problem, a non-gravitational signal and also a model to interpret a possible Dark Matter message are needed. This may be expressed in various ways, and our approach is based on so-called simplified model. We have built a new t-channel simplified model which promotes a real scalar particle as DM and a vector-like fermion as mediator, dubbed the Vector-like Portal. In our framework, there are very few free parameters, the DM mass, the mass of the mediator and at least one Yukawa coupling. We have discovered an intriguing feature in the annihilation cross-section, a d-wave suppression in the limit of light final state fermions (compared to the DM mass). This seemingly innocuous observation will turn out to be crucial both for thermal freeze-out and for indirect searches for DM, for which higher order effects become relevant. In particular, we have performed a comprehensive analysis of the impact of next-to-leading order corrections to the annihilation cross-section, including coannihilation, as well as on elastic scattering processes. We have exploited the complementarity of direct, indirect and collider searches to set constraints on the parameter space of some simple vector-like portal scenarios, including coupling to Standard Model leptons, light quarks and the top quark. In addition, we have studied the phenomenological consequences of electroweak corrections and the detectability ofour candidate. / Bien que presque un siècle ait passé depuis sa découverte, et malgré les progrès scientifiques et technologiques de notre société, la nature de la matière noire (MN) est un mystère irrésolu. C’est un grand challenge pour la communauté scientique, car sa découverte signifierait la compréhension de ce qui semble constituer 80 % du contenu en matière de l’univers. Nous disons “semble” car jusqu’à présent toutes les évidences de MN sont purement gravitationnelles. Cela implique que ce que nous appelons matière noire pourrait être soit une manifestation de notre compréhension incomplète de la gravité à grandes échelles, soit une nouvelle forme de matière, en particulier un nouveau type de particule élémentaire. Parmi la pléthore de candidats de MN possibles, ce travail considèrera la Weakly Interactive Massive Particle (WIMP). A ce jour, la valeur observée de l’abondance relique est le seul paramètre solide sur lequel nous pouvons compter, et la WIMP est le candidat qui, par un élégant mécanisme de production, donne un résultat pour l’abondance relique en accord avec les observations cosmologiques. Pour démontrer que cela est en effet l’explication valide du problème de la MN, un signal non gravitationnel ainsi qu’un modèle pour interpréter un possible message de MN sont requis. Cela peut s’exprimer de plusieurs façons, et notre approche est basée sur les modèles dits simplifiés. Nous avons construit un nouveau modèle simplifié avec le canal t qui promeut une particule scalaire réel comme MN et un fermion de type vector-like comme médiateur, et communément appelé le portail vector-like. Dans notre cadre, il y a très peu de paramètres libres, la masse de la MN, la masse du médiateur et au moins un couplage de Yukawa. Nous avons découvert une caractéristique intrigante dans la section efficace d’annihilation, une suppression de type d-wave dans la limite de fermions légers dans l’état final (en comparaison avec la masse de la MN). Il se trouve que cette observation, qui semble anodine au premier abord, est cruciale pour le freeze-out et pour les recherches indirectes de MN, pour lesquelles les effets aux ordres supérieurs deviennent relevants. En particulier, nous avons réalisé une analyse compréhensive de l’impact des corrections après l’ordre dominant de la section efficace d’annihilation, ainsi que des processus de diffusion élastique. Nous avons exploité la complémentarité des recherches directes, indirectes et aux collisionneurs afin de contraindre l’espace des paramètres de quelques scénarios simples de portails vector-like, dont le couplage au leptons du Modèle Standard et au quark top. De plus, nous avons étudié les conséquences phénoménologiques des corrections électrofaibles, et la détectabilité de notre candidat. / Option Physique du Doctorat en Sciences / info:eu-repo/semantics/nonPublished

A search for new phenomena in final states with one or more energetic jets and large missing transverse momentum, ETmissT, is presented. An integrated luminosity of 20 fb-1 is collected from √s = 8 TeV pp collisions at the LHC with the ATLAS detector during 2012 operations. A selection criteria is imposed requiring events to have monojet signatures, with ETmissT > 350 GeV and no identified leptons. Standard Model backgrounds and systematics uncertainties are estimated using a maximum likelihood procedure. The number of events passing this selection criteria is in good agreement with Standard Model expectations. These events are then divided up into three orthogonal signal regions based on the outputs of two Random Forest classifiers trained to classify invisible decays of the Higgs boson produced through the vector boson fusion and Higgs-strahlung production modes. These results are then interpreted in terms of three different Higgs-portal models and translated into upper limits on WIMP-nucleon cross-sections for comparison with direct detection experiments. / Graduate

The cosmological constant + cold dark matter (ΛCDM) theory is the 'standard model' of cosmology. Encoded in it are extremely accurate descriptions of the large scale structure of the Universe, despite a very limited number of degrees of freedom. The model struggles, however, to explain some measurements on galactic and smaller scales. The shape of the dark matter distribution toward the centres of galaxies is predicted to be steeply increasing in density ('cuspy') by the theory, yet observations of the rotation curves of some galaxies suggest that it instead reaches a central density plateau (a 'core'). This discrepancy is termed the 'cusp-core problem'. I propose a new way of quantifying this problem as a diversity in the central mass content of galaxies. This characterization does not distinguish between dark and ordinary ('baryonic') matter, but the apparent problem is so severe that the signature of the cusp-core discrepancy is still obvious. By formulating the problem in this way, several uncertain modelling steps are effectively removed from the discussion, allowing for a more narrowly focussed examination of remaining steps in the analysis. My subsequent comparison of recent results from galaxy formation simulations and observed galaxies in the space of the baryonic Tully-Fisher relation (BTFR) reveals some galaxies with an apparent anomalously low dark matter content not only in the centre, but out to the largest measurable radii. These objects are very difficult to explain within the ΛCDM framework; the most plausible interpretation which emerges is that the effect of systematic uncertainties in modelling the kinematics in these galaxies – particularly in the estimate of their inclinations – has been substantially underestimated. This motivates a re-examination of rotation curve measurement methods. I use a collection of simulated galaxies to demonstrate that, when these are synthetically 'observed' and modelled analogously to real galaxies, non-circular motions present in the gas discs give the appearance of cores, even though all of the simulated galaxies have central cusps. The errors are large enough to reproduce the full width of the observed scatter in rotation curve shapes. Provided the simulations produce sufficiently faithful models of real galaxies, these modelling errors could constitute a solution to the cusp-core problem within the ΛCDM paradigm. Regardless, the kinematic models must be better understood before drawing any strong cosmological conclusions. / Graduate