Leading two-loop corrections to the Higgs boson masses in SUSY models with Dirac gauginos

We compute the two-loop O(as*at) corrections to the Higgs boson masses in supersymmetric extensions of the Standard Model with Dirac gaugino masses. We rely on the effective-potential technique, allow for both Dirac and Majorana mass terms for the gluinos, and compute the corrections in both the DRbar and on-shell renormalisation schemes. We give detailed results for the MDGSSM and the MRSSM, and simple approximate formulae valid in the decoupling limit for all currently-studied variants of supersymmetric models with Dirac gluinos. These results represent the first explicit two-loop calculation of Higgs boson masses in supersymmetric models beyond the MSSM and the NMSSM.Comment: 36 pages, 5 figures; v2: version published in JHE

Supersymmetric and non-supersymmetric models without catastrophic Goldstone bosons

The calculation of the Higgs mass in general renormalisable field theories has been plagued by the so-called "Goldstone Boson Catastrophe", where light (would-be) Goldstone bosons give infra-red divergent loop integrals. In supersymmetric models, previous approaches included a workaround that ameliorated the problem for most, but not all, parameter space regions; while giving divergent results everywhere for non-supersymmetric models! We present an implementation of a general solution to the problem in the public code SARAH, along with new calculations of some necessary loop integrals and generic expressions. We discuss the validation of our code in the Standard Model, where we find remarkable agreement with the known results. We then show new applications in Split SUSY, the NMSSM, the Two-Higgs-Doublet Model, and the Georgi-Machacek model. In particular, we take some first steps to exploring where the habit of using tree-level mass relations in non-supersymmetric models breaks down, and show that the loop corrections usually become very large well before naive perturbativity bounds are reached.Comment: 45 pages, 12 figure

Matching renormalisable couplings: simple schemes and a plot

We discuss different choices that can be made when matching a general high-energy theory -- with the restriction that it should not contain heavy gauge bosons -- onto a general renormalisable effective field theory at one loop, with particular attention to the quartic scalar couplings and Yukawa couplings. This includes a generalisation of the counterterm scheme that was found to be useful in the case of high-scale/split supersymmetry, but we show the important differences when there are new heavy scalar fields in singlet or triplet representations of $SU(2)$. We also analytically compare our methods and choices with the approach of matching pole masses, proving the equivalence with one of our choices. We outline how to make the extraction of quartic couplings using pole masses more efficient, an approach that we hope will generalise beyond one loop. We give examples of the impact of different scheme choices in a toy model; we also discuss the MSSM and give the threshold corrections to the Higgs quartic coupling in Dirac gaugino models.Comment: 59 pages, 7 figures. v2: added some explanations. Matches published versio

‘A Red-Green Lighthouse’ The city of Trondheim in Norwegian politics

In 2003 a new majority in Trondheim’s City Hall started to vigorously implement a radical programme to reclaim the public sector, re-municipalize service provision and expand the level and quality of social services. At the same time, the city eliminated the budget deficit inherited from the previous regime

Rammefaktorer og tilpasset opplæring : et kvalitativt studie fra to offentlige skoler og to friskoler

Problemområde Intensjonen med oppgaven har vært å belyse hvordan rammefaktorer kan påvirke opplæringen. I tråd med dette er oppgavens problemstilling som følger; ”Hvordan påvirkes læreres yrkesutøvelse av de rammefaktorer som omkretser opplæringssituasjonen? - En studie hvor læreres opplevelse av ’tilpasset opplæring’ brukes til å synliggjøre sammenhenger mellom yrkesutøvelse og rammebetingelser i friskoler og i offentlige skoler.” For å belyse forskningsspørsmålet har rammefaktorteori blitt brukt som teoretisk rammeverk. De begreper, og antakelser om sammenhenger mellom disse, som har vært med på å styre intervjuenes innhold og hvilke deler av virkeligheten som er forsøkt avdekket, er valgt ut med utgangspunkt i rammefaktorteori. ’Tilpasset opplæring’ har blitt brukt som et medierende begrep for å belyse lærernes opplevelse av de rammer som omkretser opplæringssituasjonen. Læreres opplevelse av rammer både på friskoler og offentlige skoler har blitt undersøkt. Dette ble både gjort for å få øke sannsynligheten for at lærere med ulike oppfatninger er med i respondentgruppen, og for å tilføre ytterligere en dimensjon til undersøkelsen. Metode Empirien er skaffet til veie for å fange opp hvilke oppfatninger lærere har av muligheter og begrensninger for å ’tilpasse opplæringen’, og hvordan disse henger sammen med rammer som påvirker opplæringen på friskoler og i offentlige skoler. Kvalitative metoder generelt, og fokusgrupper spesielt, har vært godt egnet til å få fram nødvendige nyanser i lærernes tanker og opplevelser. Datamaterialet i denne oppgaven er derfor hentet inn gjennom fire fokusgruppeintervjuer. To av disse ble avholdt på friskoler, og to på offentlige skoler. Utfallet av disse intervjuene er analysert ut fra kategorier som ble laget med bakgrunn i rammefaktorteori. Analysene kan synliggjøre sammenhenger som gjelder for akkurat disse lærerne på disse skolene. Å generalisere utover dette er ikke mulig. Tendensene som er funnet i undersøkelsen kan imidlertid undersøkes nærmere, og muligens verifiseres, i senere forskningsprosjekter. På denne måten kan resultater fra flere undersøkelser til sammen bidra til å øke sannsynligheten for at funn kan ha gyldighet for lærerpopulasjonen generelt. Resultater Gjennom analyser av utsagnene som lærerne brukte for å beskrive deres opplevelse av hvorledes ’tilpasset opplæring’ fungerer på deres skole, er det mulig å si noe om rammers påvirkning på opplæringssituasjonen til lærerne i materialet. Noen av hovedfunnene kan sammenfattes i følgende punkter: • Formelle rammebetingelser ser ut til både å ha innvirkning på skolesituasjonen generelt, og for mulighetene lærere har for å tilpasse opplæringen til den enkelte, spesielt. Friskolene ser i større grad enn de offentlige skolene ut til å ha ”lokal frihet”, både økonomisk og ideologisk. • Det synes å være et noe større foreldreengasjement og deltakelse i skolen blant friskoleforeldrene, enn blant foreldrene i den offentlige skolen. Gjennom de krav foreldre stiller, ser det derved ut til at nærsamfunnets rammer påvirker lærernes yrkesutøvelse mer på de to friskolene, enn på de offentlige skolene. • De indre rammenes utforming varierer fra skole til skole. Det påtagende er imidlertid at det kan se ut til at lærere på skoler med nokså like betingelser, kan oppfatte og utnytte rammene på svært forskjellige måter. Det ser dermed ut til at en skoles indre rammer får betydning for opplæringssituasjonen både gjennom de faktiske begrensningene disse setter, og gjennom hvordan lærerne tolker disse rammene og dermed hvordan de lar dem påvirke sin yrkesutøvelse. Rammers påvirkning, i dette tilfellet på opplæringssituasjonen, ser i stor grad ut til å avhenge av, og variere med, lærernes opplevelse av rammene. Dette gjelder for alle de tre nivåene over. ’Tilpasset opplæring’ er et sentralt begrep i den norske skolen. Det ser allikevel ikke ut til at de lærerne jeg har intervjuet er komfortable med hvordan dette skal iverksettes i praksis. Det er grunn til å tro at lærere ville hatt god nytte av flere utdypende diskusjoner omkring hvorledes dette bedre kan la seg gjennomføre i opplæringssituasjonen

N-loop running should be combined with N-loop matching

We investigate the high-scale behaviour of Higgs sectors beyond the Standard Model, pointing out that the proper matching of the quartic couplings before applying the renormalisation group equations (RGEs) is of crucial importance for reliable predictions at larger energy scales. In particular, the common practice of leading-order parameters in the RGE evolution is insufficient to make precise statements on a given model's UV behaviour, typically resulting in uncertainties of many orders of magnitude. We argue that, before applying N-loop RGEs, a matching should even be performed at N-loop order in contrast to common lore. We show both analytical and numerical results where the impact is sizeable for three minimal extensions of the Standard Model: a singlet extension, a second Higgs doublet and finally vector-like quarks. We highlight that the known two-loop RGEs tend to moderate the running of their one-loop counterparts, typically delaying the appearance of Landau poles. For the addition of vector-like quarks we show that the complete two-loop matching and RGE evolution hints at a stabilisation of the electroweak vacuum at high energies, in contrast to results in the literature.Comment: 16 pages, 11 figures; v2: title changed, accepted for publication in PR

Using Integrated Assessment Models to Achieve the Paris Climate Target

Integrated assessment models (IAMs) have become central tools in global assessments of how to achieve the Paris climate target. But how reliable are the insights that can be drawn from IAMs? This thesis identifies and begins to assess three challenges associated with the use of IAM ensembles and individual IAMs to draw insights on climate mitigation. First, it highlights the importance of model independence for the robustness of insights that can be drawn from IAM ensembles. It develops a method that uses model documentation to construct a model family tree and uses this method to identify likely model dependencies between IAMs in the IPCC’s 5th assessment report (AR5). The analysis shows that the 14 most influential IAMs in AR5 form three branches, the largest of which (including MERGE, MESSAGE, MERGE-ETL, REMIND, WITCH, and BET) is responsible for about half of the scenarios in AR5. The model documentation also indicates that an expanding set of policy questions has incentivised a continuous increase in the detail and scope of IAMs over time. The findings give reason to believe that the diversity of model choices and assumptions included in the AR5 IAM ensemble might be limited. Second, it argues, based on a debate on values in science in philosophy, that the exclusively positive estimates of the cost of mitigation in AR5 are problematic because they don’t capture the full range of cost estimates found in the literature and because the uncertainty of the cost of mitigation is important. A review of the literature reveals that general equilibrium models, which are responsible for all the cost estimates in AR5, can (despite claims to the contrary) be modified to generate net negative costs, but that few of the IAMs in AR5 include mechanisms that typically contribute to net negative costs. It is also found that the model intercomparison studies that are responsible for most of the AR5 cost estimates focused only on aspects that increase the cost of mitigation. Overall, this gives reason to believe that the AR5 IAM ensemble might be biased against net negative mitigation costs. Third, it shows that predictions of climate policy impacts based on the Future Technology Transformations (FTT) simulation model are highly sensitive to a scaling parameter whose correct value is deeply uncertain. This result, which is obtained using Monte Carlo analysis and uniform and independent distributions (around ±50% of default values) for investor discount rates, technology build times, technology lifetimes, learning rates, and the scaling factor in a global sensitivity analysis, shows that the use of diffusion theory to derive technology deployment – which is seen by those who designed FTT to present a unique feature of the model – does not in itself ensure reliable predictions. In fact, the result indicates that predictions from both energy system optimisation models, which are more widely used, and FTT depend on similar unknowns related to future rates of technological change. Based on these three challenges, the thesis concludes, a diversity of model choices and assumptions is crucial for ensuring robust insights and for reflecting important uncertainties associated with IAM research

Regulation of the Melanoma Cell Adhesion Molecule Gene in Melanoma: Modulation of mRNA Synthesis by Cyclic Adenosine Monophosphate, Phorbol Ester, and Stem Cell Factor/c-Kit Signaling

The melanoma cell adhesion molecule was identified as a human melanoma-associated antigen that increases in expression as tumors increase in thickness and begin to acquire metastatic potential. Clinical and experimental evidences suggest that the development of metastatic capacity might be the consequence of increased melanoma cell adhesion molecule expression. The mechanisms for upregulation of the melanoma cell adhesion molecule during melanoma progression are, however, still poorly understood. In this study, we show that melanoma cell adhesion molecule expression is tightly regulated at the transcriptional level. Using a combination of CAT reporter assays and semiquantitative reverse transcriptase–polymerase chain reaction, we observed that cyclic adenosine monophosphate significantly increases transcription of the melanoma cell adhesion molecule in nonmetastatic melanoma cells. In metastatic cells, transcription of the gene was constitutive and could not be further increased by cyclic adenosine monophosphate. On the other hand, melanoma cell adhesion molecule promoter activity was impeded upon treatment with phorbol esters or in the presence of stem cell factor, a phenomenon which was protein kinase C-dependent. Promoter-deletion studies demonstrated that the first 196 nt of the melanoma cell adhesion molecule promoter region are sufficient to get full expression in metastatic melanoma cells. This fragment contains five binding sites for the transcription factor Sp1 and DNA mobility shift experiments showed direct binding of Sp1 to the promoter. In conclusion, our results indicate that Sp1 is sufficient to drive constitutive melanoma cell adhesion molecule expression in metastatic melanoma cells. In nonmetastatic cells, however, melanoma cell adhesion molecule expression is repressed and we speculate that stem cell factor/c-Kit signaling might be responsible for the control of melanoma cell adhesion molecule synthesis, and thus, perhaps, of melanoma progression and metastasis

The role of stigma in accessing education for people with disabilities in low and middle-income countries: a review of the evidence

People with disabilities are often subjected to stigma, which can keep them from realising their full potential and their human rights, including the right to education. The UN agenda for Sustainable Development Goals, underscores the urgent need to eliminate and ensure equal access in education to vulnerable groups, including people with disabilities. Thus, it is important to understand the different barriers and facilitators, which are preventing or enabling people with disabilities in their access to inclusive quality education. This report presents findings from a scoping review conducted to give an overview of the evidence-base on the role of stigma in accessing education for people with disabilities in low and middle-income countries (LMICs). Twenty-three articles from LMICs met the predetermined inclusion criteria. These articles described some of the ways stigma is affecting access to and equity in education, especially attitudes coming from teachers, school staff and structures, peers, parents and children's own felt stigma. In turn, these attitudes reflect societal stigma which is due to lack of knowledge and a societal view of disability, based on the medical model of impairment and limitation. There is a need for capacity building of teachers and of changing the medical view of disabilities in society. Evidence-based awareness campaigns and research on the implementation of inclusive education in low and middle-income countries is needed. ISBN: 978-82-14-06715-6publishedVersio