Cette thèse cherche à quantifier le temps de premier passage (FPT) d'un marcheur non-markovien sur une cible. La première partie est consacrée au calcul du temps moyen de premier passage (MFPT) pour différents processus non-markoviens confinés, pour lesquels les variables cachées sont connues. Notre méthode, qui adapte un formalisme existant, repose sur la détermination de la distribution des variables cachées au moment du FPT. Nous étendons ensuite ces idées à processus non-markoviens confinés généraux, sans introduire les variables cachées - en général inconnues. Nous montrons que le MFPT est entièrement déterminé par la position du marcheur dans le futur du FPT. Pour des processus gaussiens à incréments stationnaires, cette position est très proche d'une processus gaussien, hypothèse qui permet de déterminer ce processus de manière auto-cohérente, et donc de calculer le MFPT. Nous appliquons cette théorie à différents exemples en dimension variée, obtenant des résultats très précis quantitativement. Nous montrons également que notre théorie est exacte perturbativement autour d'une marche markovienne. Dans une troisième partie, nous explorons l'influence du vieillissement sur le FPT en confinement, et prédisons la dépendance en les paramètres géométriques de la distribution de ce FPT, prédictions vérifiées sur maints exemples. Nous montrons en particulier qu'une non-linéarité du MFPT avec le volume confinant est une caractéristique d'un processus vieillissant. Enfin, nous étudions les liens entre les problèmes avec et sans confinement. Notre travail permet entre autre de d'estimer l'exposant de persistance associé à des processus gaussiens non-markoviens vieillissant. / The aim of this thesis is the evaluation of the first-passage time (FPT) of a non-markovian walker over a target. The first part is devoted to the computation of the mean first-passage time (MFPT) for different non-markovien confined processes, for which hidden variables are explicitly known. Our methodology, which adapts an existing formalism, relies on the determination of the distribution of the hidden variables at the instant of FPT. Then, we extend these ideas to the case of general non-markovian confined processes, without introducing the -often unkown- hidden variables. We show that the MFPT is entirely determined by the position of the walker in the future of the FPT. For gaussian walks with stationary increments, this position can be accurately described by a gaussian process, which enable to determine it self-consistently, and thus to find the MFPT. We apply this theory on many examples, in various dimensions. We show moreover that this theory is exact perturbatively around markovian processes. In the third part, we explore the influence of aging properties on the the FPT in confinement, and we predict the dependence of its statistic on geometric parameters. We verify these predictions on many examples. We show in particular that the non-linearity of the MFPT with the confinement is a hallmark of aging. Finally, we study some links between confined and unconfined problems. Our work suggests a promising way to evaluate the persistence exponent of non-markovian gaussian aging processes.

<p>The passage efficiency of downstream migrating brown trout (Salmo trutta) smolts past two hydropower plants in the River Emån, southeastern Sweden, was evaluated by telemetry. From 26 April to 17 May 2005, 40 wild brown trout smolts were radio-tagged, and their positions were recorded daily until 14 June. Approximately 45% of the individuals passed both power plants, and 15% made it to the sea, some 28 km downstream of the power plants. About 20% of the individuals ceased migrating, residing in a lotic habitat. Mortality due to predation was 33%, and the predation rate was higher in the power plant dams than it was downstream of the power plants. Turbine-induced mortality was greater in the upper power plant (40%) than in the lower one (13%). Fish that chose the alternative routes, through the gates, swam past the upper dam faster than fish that swam through the turbines. The results confirm previous work in the river, namely that measures need to be taken to improve passage efficiency past the power plants, particularly passage of the upper power plant. Such measures are of crucial importance if the nature-like bypass channels at the power plants in Finsjö are going to have any long-term effects on the brown trout population.</p> / <p>Passageeffektiviteten för nedströms vandrande havsöringssmolt (Salmo trutta) förbi två vattenkraftverk i Emån, i sydöstra Sverige, utvärderades med telemetri. Från 26 april till och med 17 maj 2005 märktes 40 vilda havsöringssmolt med radiosändare och de positionsbestämdes dagligen till och med 14 juni. Ungefär 45% av individerna passerade båda kraftverken, och 15% klarade sig till havet, cirka 28 km nedströms kraftverken. Omkring 20% av individerna avbröt vandringen och stannade i ett lotiskt habitat. Mortalitet på grund av predation uppgick till 33%, och predationshastigheten var högre i kraftverksdammarna än nedströms kraftverken. Den turbininducerade mortaliteten var högre i det övre kraftverket (40%) än i det nedre (13%). Det gick fortare att passera den övre kraftverksdammen för fisk som valde de alternativa rutterna, genom dammluckorna, jämfört med att passera genom turbinerna. Dessa resultat bekräftar tidigare studier i ån, nämligen att åtgärder krävs för att förbättra passageeffektiviteten förbi kraftverken, i synnerhet passagen av det övre kraftverket. Sådana åtgärder är av avgörande betydelse om de naturlika fiskvägarna vid kraftverken i Finsjö ska få några långsiktiga effekter på havsöringspopulationen.</p>

The passage efficiency of downstream migrating brown trout (Salmo trutta) smolts past two hydropower plants in the River Emån, southeastern Sweden, was evaluated by telemetry. From 26 April to 17 May 2005, 40 wild brown trout smolts were radio-tagged, and their positions were recorded daily until 14 June. Approximately 45% of the individuals passed both power plants, and 15% made it to the sea, some 28 km downstream of the power plants. About 20% of the individuals ceased migrating, residing in a lotic habitat. Mortality due to predation was 33%, and the predation rate was higher in the power plant dams than it was downstream of the power plants. Turbine-induced mortality was greater in the upper power plant (40%) than in the lower one (13%). Fish that chose the alternative routes, through the gates, swam past the upper dam faster than fish that swam through the turbines. The results confirm previous work in the river, namely that measures need to be taken to improve passage efficiency past the power plants, particularly passage of the upper power plant. Such measures are of crucial importance if the nature-like bypass channels at the power plants in Finsjö are going to have any long-term effects on the brown trout population. / Passageeffektiviteten för nedströms vandrande havsöringssmolt (Salmo trutta) förbi två vattenkraftverk i Emån, i sydöstra Sverige, utvärderades med telemetri. Från 26 april till och med 17 maj 2005 märktes 40 vilda havsöringssmolt med radiosändare och de positionsbestämdes dagligen till och med 14 juni. Ungefär 45% av individerna passerade båda kraftverken, och 15% klarade sig till havet, cirka 28 km nedströms kraftverken. Omkring 20% av individerna avbröt vandringen och stannade i ett lotiskt habitat. Mortalitet på grund av predation uppgick till 33%, och predationshastigheten var högre i kraftverksdammarna än nedströms kraftverken. Den turbininducerade mortaliteten var högre i det övre kraftverket (40%) än i det nedre (13%). Det gick fortare att passera den övre kraftverksdammen för fisk som valde de alternativa rutterna, genom dammluckorna, jämfört med att passera genom turbinerna. Dessa resultat bekräftar tidigare studier i ån, nämligen att åtgärder krävs för att förbättra passageeffektiviteten förbi kraftverken, i synnerhet passagen av det övre kraftverket. Sådana åtgärder är av avgörande betydelse om de naturlika fiskvägarna vid kraftverken i Finsjö ska få några långsiktiga effekter på havsöringspopulationen.

La première partie de cette thèse est consacrée à l'élaboration théorique de processus adiabatiques permettant le transfert de population entre un état initial et un état cible d'un système quantique. La stratégie du passage adiabatique parallèle pour laquelle les paramètres de couplage sont conçus de telle sorte que la différence des valeurs propres du système reste constante à chaque instant, permet de minimiser à zéro les transitions non-adiabatiques données par la formule DDP. Cette technique permet de combiner à la fois l'efficacité énergétique des méthodes impulsion-pi et la robustesse du passage adiabatique. La seconde partie de cette thèse concerne les effets de la dissipation sur le passage adiabatique. La formule de probabilité de transition d'un système à deux niveaux tenant compte des effets de la dissipation est établie. Cette formule permet de reformuler la solution générale d'un système dissipatif à deux niveaux dans la limite adiabatique qui est valable au-delà du régime de faible dissipation.

Dans la perspective d’une anthropologie ontologique, la thèse vise à mieux comprendre les continuités et les transformations au sein des rites de passage chez les Inuit du Nunavik, depuis leur conversion au christianisme jusqu’au contexte actuel. Les rites de la grossesse, de l’accouchement, et de la naissance, y sont décrits en détail, tout comme le processus de dénomination de l’enfant, puis les rites de la première fois. Cette ethnographie mobilise une démarche comparative régionale, et s’appuie sur plusieurs collaborations avec des institutions du Nunavik. Les séquences de ces rites de passage sont dès lors analysées à la fois comme des temps forts de la construction de la personne, et comme des témoins de la résilience manifestée par la culture inuit. Au cœur de la socialisation de l’enfant, ces rites apparaissent en effet avoir contribué à transmettre certains principes culturels grâce auxquels différents éléments de la cosmologie chrétienne ont pu être adaptés et incorporés. Ces rites auraient alors participé de l’actualisation de la cosmologie inuit au XXe siècle, et en particulier de la réorganisation des relations que les humains entretiennent avec différents êtres non-humains. En transmettant jusqu’à aujourd’hui les principes ontologiques fondant ces relations, après y avoir intégré plusieurs éléments de la tradition chrétienne, ces rites suggèrent de considérer l’importance du rôle socialisateur des êtres non-humains – fœtus, défunts, animaux, esprits – dans l’éducation enfantine, et appellent une réflexion sur l’extension de la notion de personne aux êtres non-humains. / Using ontological anthropology as a theoretical framework, this thesis aims to better understand the continuities and transformations in the rites of passage among the Inuit of Nunavik, since their conversion to Christianity until today. The rites of pregnancy, childbirth, and birth, are described in detail, as well as the naming process of the child, and the rites of the first time. This ethnography uses a regional comparative approach, and is based on several collaborations with some institutions of Nunavik. The sequences of these rites of passage are therefore analyzed both as a highlight of the construction of the person, and as witnesses to the resilience shown by the Inuit culture. At the heart of the socialization of children, these rites indeed appear to have contributed to convey certain cultural principles by which different elements of the Christian cosmology could be adapted and incorporated. These rites would thus have been instrumental in updating the Inuit cosmology of the twentieth century, and more precisely in reorganizing of relationships that humans have with various non-human beings. Passing on, until today, the ontological principles underlying these relations, and after incorporating several elements of the Christian tradition, these rites suggest the importance of acknowledging the socializing role played by many non-human beings – foetuses, deceased, animals, spirits - in early education. It therefore implies to address a sensitive question, that is, the extension of the notion of person to non-humans beings.

J'ai présenté tout d'abord l'examen de l'évolution des dispositions mises en œuvre dans les écoles de formation des maîtres. Puis, l'analyse du contexte social qualifié d' «hypermoderne » (Aubert 2006) m'a permis de confirmer l'affaiblissement d'un soutien institutionnel à la construction identitaire professionnelle. A l'aide de la notion anthropologique de ''rite de passage'', j'ai pu appréhender les fonctions essentielles de la marque physique et le rôle primordial du groupe dans les processus de changement identitaire. Dans la deuxième partie, j'ai analysé le contenu de trois entretiens, menés auprès de débutant-e-s, réalisés selon une démarche clinique à orientation psychanalytique (Blanchard-Laville et al, 2005). Cette méthodologie m'a permis d'approcher les traces de processus inconscients qui viendraient perturber la construction d'un « soi-professionnel » (Abraham 1984). De plus, j'ai envisagé par quelles modalités les discours institutionnels prendraient part dans ces processus.Enfin, j'ai présenté les conditions d'un atelier d'écriture proposé à de futurs enseignant-e-s que j'ai pu mettre en oeuvre dans le cadre de mes missions de formatrice. Cette présentation est complétée par l'analyse d'entretiens cliniques auprès de deux participantes aux ateliers. La tentative d'un regard clinique sur les textes produits et l'analyse du contenu des entretiens ont permis de consolider l'hypothèse selon laquelle un récit de soi, pourrait prendre valeur d'un « étayage psychique » à la construction identitaire professionnelle. / I firstly presented the review of the evolution of the provisions implemented in teacher training schools. Then, the analysis of qualified social context of "hypermodern" (Aubert 2006) allowed me to confirm the weakening of institutional support to professional identity construction. Using anthropological concept of 'rite of passage' 'I was able to grasp the essential functions of the physical mark and the primary role of the group in identity change process. In the second part, I analyzed the content of three interviews conducted with beginner-es, made according to a clinical approach to psychoanalytic orientation (Blanchard-Laville et al). This methodology has allowed me to approach the traces of unconscious processes that would disrupt the construction of a "so-professional" (Abraham Ada date). Moreover, by what I considered institutional discourse modalities take part in these processes. Finally, I presented the terms of a writing workshop offered to future teachers are I could implement within my formative missions. This presentation is supplemented by analysis of clinical interviews with two workshop participants. The attempt of a clinical look at the products and the content analysis of interviews texts have strengthened the hypothesis that a self-narrative, could take value of a "psychic shoring" vocational identity construction.

Syftet med studien var att undersöka hur äldre erfar att livssituationen förändrats när de inte har haft stöd från hemtjänst till att beviljas insatser från hemtjänst. För att undersöka detta genomfördes halvstrukturerade intervjuer på en dagverksamhet med fem äldre personer som har hemtjänst. För att analysera materialet användes innehållsanalys, och teman användes för att kategorisera insamlade data. Dessa teman var livet innan hemtjänst, hälsa, livet efter hemtjänst och känslor kring livsförändring. För att tolka resultatet användes begreppen status passage, divestment passage och coping. Resultatet visar att förändringen av livssituationen börjar med att den fysiska förmågan försämras, antingen med ökande ålder eller genom sjukdom och skador. I och med försämrad fysisk förmåga blir de äldre beroende av stöd från hemtjänst i vardagen, och vardagslivet blir då styrt av hemtjänstens tider och rutiner. Denna förändring som vi har analyserat med hjälp av passage begreppen upplevs av några som negativ, medan den även i ett fall beskrivs som en i övergående positiv erfarenhet. Den sistnämnda erfarenheten föreslår vi ska benämnas som investment passage. För att hantera dessa förändringar av livssituationen används olika strategier, framförallt känslomässiga sådana. / The purpose of this study was to investigate how the elderly experience life changes when they have not received support from formal home care to receive home care services. To investigate this, half-structured interviews were conducted on a day-care facility, with five elderly people who receive formal home care service. In order to analyze the material, content analysis was used, and themes were used to categorize the collected data. These themes were life before home care, health, life after home care and feelings about life change. To interpret the result, the terms status passage, divestment passage and coping was used. The result shows that the change of life situation begins with the physical ability deteriorating, either with increasing age or through illness and injury. With the deterioration of physical ability, the elderly are dependent on home care services in their daily lives, and life is then controlled by the times and routines of the home care service. This change that we have analyzed using passage terms, some experience in a negative way while in one case it is described as a positive experience. We suggest that this positive experience should be called investment passage. To handle these changes of life situation different strategies are used, especially emotional ones.

Les marches aléatoires avec recherche de cible peuvent modéliser des réactions nucléaires ou la quête de nourriture par des animaux. Dans cette thèse, nous identifions des stratégies qui minimisent le temps moyen de première rencontre d’une cible (MFPT) pour plusieurs types de marches aléatoires. Premièrement, pour des marches symétriques ou avec biais, nous déterminons la distribution des temps de première sortie par une ouverture dans une paroi en forme de secteur angulaire, d’anneau ou de rectangle. Nous concluons sur la minimisation du MFPT en termes de la géométrie du confinement. Deuxièmement, pour des marches alternant entre diffusions volumique et surfacique, nous déterminons le temps moyen de première sortie par une ouverture dans la surface de confine- ment. Nous montrons qu’il existe un taux de désorption optimal qui minimise le MFPT. Nous justifions la généralité de l’optimalité par l’étude des rôles de la géométrie, de l’adsorption sur la surface et d’un biais en phase volumique. Troisièmement, pour des marches actives composées de phases balistiques entrecoupées par des réorientations aléatoires, nous obtenons l’expression du taux de réorientation qui minimise le MFPT en géométries sphériques de dimension deux ou trois. Dans un dernier chapitre, nous modélisons le mouvement de cellules eucaryotes par des marches browniennes actives. Nous expliquons pourquoi le temps de persistance évolue expo- nentiellement avec la vitesse de la cellule. Nous obtenons un diagramme des phases des types de trajectoires. Ce modèle minimal permet de quantifier l’efficacité des processus de recherche d’antigènes par des cellules immunitaires. / Random search processes can model nuclear reactions or animal foraging. In this thesis, we identify optimal search strategies which minimize the mean first passage time (MFPT) to a target for various processes. First, for symmetric and biased Brownian particles, we compute the distribution of exit times through an opening within the boundary of angular sectors, annuli and rectangles. We conclude on the optimizability of the MFPT in terms of geometric parameters. Second, for walks that switch between volume and surface diffusions, we determine the mean exit time through an opening inside the bounding surface. Under analytical criteria, an optimal desorption rate minimizes the MFPT. We justify that this optimality is a general property through a study of the roles of the geometry, of the adsorption properties and of a bias in the bulk random walk. Third, for active walks composed of straight runs interrupted by reorientations in a random direction, we obtain the expression of the optimal reorientation rate which minimizes the MFPT to a centered spherical target within a spherical confinement, in two and three dimensions. In a last chapter, we model the motion of eukaryotic cells by active Brownian walks. We explain an experimental observation: the persistence time is exponentially coupled with the speed of the cell. We also obtain a phase diagram for each type of trajectories. This model is a first step to quantify the search efficiency of immune cells in terms of a minimal number of biological parameters.

The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales than estimated for the entire North Pacific several decades ago. An understanding of how this growing population is repopulating traditional foraging grounds will benefit from detailed investigations of their prey preferences and trends in whale abundance and distribution relative to those prey. This dissertation examines these issues from late May until early September 2008 in Frederick Sound and Stephens Passage, a Southeast Alaskan feeding area historically used by humpback whales. The foundation for the study is an analysis of the life histories and abundance patterns of euphausiids, the principal prey of humpbacks in the area, during late spring and summer. Four species, Thysanoessa raschii, T. longipes, T. spinifera, and Euphausia pacifica, were identified in plankton net samples collected at random locations throughout the study site (n = 49) and in locations where a strong scattering layer was observed on a 120 kHz echosounder (n = 48). Both sample types varied in euphausiid species composition. Abundance patterns of immature euphausiids coupled with observations of females carrying spermatophores indicated differences between species in spawning schedules. Thysanoessa spp. began spawning in early April with the spring phytoplankton bloom and continued until late June, whereas E. pacifica began spawning in early June and continued until late August. This protracted recruitment of immature euphausiids was geographically widespread throughout the summer in contrast to adults, which, although present all summer, were found primarily in slope and shallow (< 100 m) areas. To determine if humpback whales preferred one euphausiid species or life-stage over another, net sample and hydroacoustic data collected in the vicinity of whales were compared to similar data collected in random locations throughout the study site. This revealed that whales targeted dense aggregations of adult euphausiids, but did not discriminate between the various species, which was surprising because of presumed differences in the energy density linked to their different spawning schedules. Additionally, whales did not spend time in areas with concentrations of immature euphausiids, which were likely not large enough during the study period to be suitable prey. With this preference for adult euphausiids, the abundance and distribution patterns of humpbacks were examined in relation to prey availability. Whale abundance was lowest at the beginning of the study in late May at ca. 68 whales and peaked in late July at ca. 228 animals – approximately 12% of the region’s estimated abundance for the study year. This study did not detect a concomitant increase in the availability of adult euphausiids, which is unsurprising since immature euphausiids would not recruit into the adult population until after the end of the study, and post-spawning mortality and predation pressure is presumably high during this time. Instead, whales clustered increasingly around comparatively fewer prey as the summer progressed. These observations, combined with a plateau in whale abundance after July, suggest that their abundance in the area was limited by euphausiid availability. Estimates of whales using the study site during the summer have remained similar over several decades despite a dramatic increase in humpback numbers in Southeast Alaska and elsewhere in the North Pacific. The results from this study suggest that, although the study site remains important seasonally to some whales, it is not a significant source of prey responsible for regional population growth in general. More likely, it is part of a network of feeding areas that has influenced the population trend. Further insight into these and the other issues raised in this dissertation could come from several additional analyses. An extended sampling season that captures the recruitment of immature euphausiids into the adult population would reveal whether a given year's prey cohort represents an important resource to whales in that same year, which has potential implications for interpreting mid-late season whale abundance patterns. As well, a photo-identification study would be useful in characterizing whale residency patterns and determining whether the abundance trends reflect a relatively small subset of the regional population using the area for most of the season or a continuous flow of a larger portion of the population. Finally, similar analyses as those outlined here but conducted in other areas within the region would provide additional insight into the network’s capacity to support the recovering whale population. / Graduation date: 2012

Samtidskonsten innebär att en mängd nya sätt att organisera presentationen av konst på har uppstått. Museet för glömska är en mindre samtidskonsthall med starkt idébaserad grund som kan sägas vara allt från ett kulturprojekt till ett idébaserat museum. Denna uppsats belyser vad Museet för glömska är och hur det görs i ett ANT-perspektiv. En del av uppsatsen är också att se hur en organisation som Museet för glömska låter sig studeras. Syftet med uppsatsen är att öka förståelsen för icke-traditionella museum och samtidskonsthallars organisation. Detta genom att synliggöra de förbindelser och relationer som bildar Museet för glömska. Tidigare studier av har visat att problematiken med samtidskonsten och dess organisering är att konsthallarna står i en beroendeställning till finansiärer varför det kritiska perspektiv som kännetecknar samtidskonsten kan vara svår att åstadkomma. Därför finns det anledning att studera alternativa organisationsformer. Museet för glömska undgår i viss mån denna problematik eftersom verksamheten sker på ideell grund. För att beskriva hur förbindelserna inom Museet för glömska hålls på plats använda begreppet obligatorisk passagepunkt, vilket kan sägas vara ett sätt att belysa hur makten fördelas i en organisation och vilka strategier som används för att bibehålla en maktposition. För att ytterligare beskriva vad Museet för glömska är och hur det görs används också begreppen objektskapande- och rumsligt nätverksperspektiv. Museet för glömska består, i ett ANT-perspektiv, av två kretslopp. Ett litet för varje utställningstillfälle och ett stort som beskriver Museet för glömskas identitet. Det lilla kretsloppet består av delarna utställningsidén, konstnärerna, konstverken, platsen och finansieringen. Det stora innehåller delarna utställningar, Medier utan minne och icke-platsen samt anti-grupperna museer, akademin, media och konstvärlden. Den sammanhållande faktorn för båda kretsloppen är en obligatorisk passagepunkt i form av talespersonerna och en obligatorisk icke-passagepunkt i form av artikeln Medier utan minne. Talespersonernas strategier för att bevara nätverket varierar beroende på vilken aktör i nätverket som ska intresseras. I ett objektskapande nätverksperspektiv är de små kretsloppen och det stora kretsloppet olika, men sammankopplade, objekt som skapar Museet för glömska. I ett rumsligt nätverksperspektiv existerar endast ett litet kretslopp, det som för tillfället är aktivt. När kretsloppet övergår till att inte länge vara aktivt så övergår det till att vara en del av det stora kretsloppets rumsliga nätverksform genom att det då endast existerar på Museet för glömskas webbsida. Jag hävdar genom uppsatsen att Museet för glömska kan ses på många olika sätt men att det i min uppsats ska förstås som en icke-organisation bestående av två kretslopp som hålls samman av en obligatorisk icke-passagepunkt i form av Medier utan minne och en obligatorisk passagepunkt i form av två talespersoner vars kommunikationer med kretsloppens olika delar och utpekandet av anti-grupper är essentiell för att Museet för glömska ska kunna bibehålla sin homeomorfism. Studien bidrar till att öka förståelsen för icke-traditionella konsthallar och museer genom att utvidga vad idébaserade museum kan vara och genom att visa på anti-gruppernas betydelse för icke-traditionella konsthallars identitetsskapande. Utöver detta visar också uppsatsen hur icke-organisationer kan studeras. / The emergence of contemporary art implied many new ways of organizing and presenting art. The Museum of Forgetting is a small and nomadic contemporary art gallery with a strong idea-based foundation. This thesis describes, what the Museum of Forgetting is and how it is made through an Actor Network Theory-perspective. Because of the complexity in what Museum of Forgetting is, it is also relevant to examine how an organization such as Museum of Forgetting can be studied. The purpose of this thesis is to increase the understanding of non-traditional museums and contemporary art galleries by displaying the associations with and within the Museum of Forgetting. Previous studies of contemporary art have shown that one problem of contemporary art and its organization is the dependence on external financiers. Therefore, the critical perspective, characterizing contemporary art, can be difficult to achieve. Because of this, there is reason to study alternative organizational forms of presenting and organizing art. This thesis increases the understanding of non-traditional art galleries and museums by expanding what idea-based museums can be and by showing the importance of anti-groups for the creation of the identities of non-traditional art galleries and museums. The empirical and analytical findings show, that the Museum of Forgetting, through an ANT perspective, consists of two cycles. A small one, that is actualized at each exhibition and a large one, describing the identity of the Museum of Forgetting. The small cycle consists of the following units: the exhibition-idea, the artists, the artworks, the place and the financing. The large cycle consists of: exhibitions, the article ”Media without memory” and non-location as well as anti-groups. The unifying factors for both cycles are one obligatory passage point manifested in two spokespersons and one obligatory non-passage point manifested in the article Media without memory. The spokespersons strategies to maintain their position as obligatory passage point varies, depending on which actor to enrol in the network. In essence, according to my findings, the Museum of Forgetting should be understood as two cycles which are coalesced by an obligatory non-passage point, manifested in Media without memory and an obligatory passage point, manifested in two spokespersons, whose communications with the different parts of the cycles and identification of anti-groups, are essential for maintaining the homeomorphism of the Museum of Forgetting.