Mörk materia, den osynliga och hypotetiska formen av materia som förutsägs av våra bästa teorier, har än så länge undkommit våra mest direkta detektionsförsök vilket har motiverat fysiker till att komma på nya och desto mer invecklade sätt att ta reda på dess sanna natur. Ett sådant sätt som verkar ha fångat samtligas intresse på senare år är möjligheten att detektera gravitationsvågor som skapatsWe perform a comprehensive cosmological analysis of stable scalar glueballs arising in pure SU(N) Yang-Mills theories focusing on N=3,4,5 which serve as natural candidates for models of self-interacting dark matter. The key characteristic of these theories is that they exhibit strong first-order confinement-deconfinement phase transitions which would give rise to a stochastic gravitational wave ba

The event generator PYTHIA can be used to simulate the hadronic part of cosmic particle showers in the atmosphere. Until now, the collision between particles and atmospheric nuclei has been modeled in a simplified way by the PythiaCascade add-on, approximating the nuclear effects. However, at present it is possible to include the Angantyr module, which constructed a detailed description of the nuc

Mitt kandidatarbete handlar om att representera den elektromagnetiska fälttensorn med matematiska objekt som kallas spinorer, bland annat genom att undersöka hur de transformeras när man byter referenssystem. Den här texten ska försöka förklara vad något av det där betyder, och sedan varför det är intressant för teoretiska fysiker. Vi börjar med transformationer. I våran vardag är vi vana med attThis thesis presents a way of representing electric and magnetic fields directly as linear combinations of products of components of Weyl spinors, without using a four-potential. First it is shown that when Lorentz transforming the spinors, these fields transform according to the tensor transformation of the electromagnetic fields. Then, by explicitly expressing the spinors in terms of a four-mome

We construct the meson-baryon chiral Lagrangian at orders two and three. The Lagrangian is constructed in the three-flavour case and with scalar, pseudoscalar, vector and axial-vector external sources included. We discuss the basic ideas of ChPT and the relations that are used to minimise the chiral Lagrangian. The relations that were used are the Bianchi identity, the Cayley-Hamilton relation, th

Albert Einstein revolutionerade mänsklighetens förståelse av universum när han 1915 skapade den allmänna relativitetsteorin som kombinerar de rumsliga dimensionerna med tiden till en dynamisk rumtid. Massiva objekt kröker rumtiden omkring sig själva, precis som du tynger ner en studsmatta när du står i mitten. Isaac Newton beskrev tidigare gravitationen som en kraft, men Einstein menade att gravitIn this thesis, the collapse of dust in a spherically symmetric inhomogeneous universe is studied. This is done using the well-known Lemaître-Tolman-Bondi model for a pressureless perfect fluid. The dynamics of the collapse are determined by the solutions to the field equations and the Misner-Sharp equation of motion, and some initial conditions are assumed in order to fix remaining degrees of fre

I många aerodynamiska höghastighets-applikationer som t.ex. raketmotorer och vindtunnlar används ett så kallat konvergerande-divergerande munstycke, vilket är en rörformad del där tvärsnittsarean först minskar och sedan ökar. Sådana munstycken används ofta för att accelerera luft till supersoniska hastigheter, vilket innebär att det flödar snabbare än ljudets hastighet som är ungefär 343 m/s. Vid This thesis investigates the potential of using Fourier neural operators to predict subsonic and supersonic flows in converging-diverging nozzles, which includes complex flow phenomena such as shock waves. Two different data sets were generated using the Euler equations for fluid flow, one based on analytical relations for a quasi one-dimensional nozzle and another one which was created by numeric

This study was conducted to better understand the complex behavior of dual-fuel diesel-ammonia combustion in compression ignition engines, with the aim of developing a simulation model that could replicate experimental results. The work specifically explores how changes in modeling parameters—such as swirl intensity and initial temperature—affect fuel-air mixing, ignition behavior, and emissions f

The purpose of this study is to investigate the factors determining continuous user-engagement for the elements Avanza Svajper and Milstolpar. By analyzing qualitative insights from both users and Avanza representatives, and interpreting the findings through the lenses of Self-Determination Theory, the Octalysis Framework, and the MDA Framework, this study provides a deeper understanding of the st

För att byggbranschen ska kunna uppnå de klimatmål som satts upp måste det ske en förändring. Förändringarna måste bidra till minskade utsläpp samtidigt som den byggtakt som krävs upprätthålls. Idag står bygg- och fastighetssektorn för mer än en femtedel av Sveriges koldioxidutsläpp, där värmeisoleringen är en bidragande orsak till utsläppen. Genom att byta ut konventionell isolering och istället For the construction industry to meet the established climate targets, a transformation is necessary. These changes must lead to reduced emissions while maintaining the pace of construction. Currently, the construction and real estate sector accounts for more than one fifth of Sweden’s carbon dioxide emissions, with insulation being a contributing factor. By replacing conventional insulation with

Denna rapport redogör över utvecklingsprocessen för ett silikonfritt, läckagetätt lock för matlådan IKEA 365+, för att undvika användandet av en silikonpackning som produkten gör idag. Drivkraften bakom projektet är att silikon är ett mycket energikrävande material att producera, samt är inte i stor skala återvinningsbart idag. Rapporten använder sig av en traditionell produktutvecklingsprocess saThis report elaborates on the development process of a silicone free, leakproof seal for the lid of the IKEA 365+ food storage platform, to alleviate the need for a silicone gasket that is used for the product today. Silicone is undesirable due to the energy intensive production and because it is not recyclable at large scale. The report uses a traditional product development process along with si

Combustible dust is a widespread and often overlooked potential occupational safety hazard. Several technical solutions exist to counter this hazard, but the risk is still a continued occurrence. This master’s thesis investigates the organizational proactive risk mitigation strategies different organizations employ in this regard. This is done in two distinct subject areas: risk awareness and risk

The aim of this thesis was to study protein-ligand interactions in the binding pocket of galectin-3C and galectin-8N through X-ray crystallography. Ligands in different stages of their development state were crystallized in complex with their respective target protein. In total, two protein-ligand complexes were structurally solved for galectin-3C, and one partially for galectin-8N. The structures

With the increasing share of renewable energy sources in the energy system, an increased demand for stabilizing the grid frequency has grown, suggesting a future need for balancing services, such as manual Frequency Restoration Reserve (mFRR). A promising actor able to offer such balancing service is combined heat and power (CHP) plants due to their dispatchable power capabilities. This thesis aim

As artificial intelligence (AI) becomes increasingly embedded in organisational operations, it introduces not only efficiency but also unique information security challenges. Traditional security practices cover common threats, however, the lack of transparency in AI output and the possibility of novel attacks such as data poisoning and phishing attacks show that these systems are poorly equipped

Denna studie undersöker hur arbetsmetoder anpassas inom AI-projekt, särskilt när dessa bygger på generativ AI. Genom kvalitativa intervjuer med fem utvecklare och projektledare inom olika organisationer analyseras hur man hanterar osäkerhet, experimentellt arbete och snabba iterat-ioner inom AI-projekt. Resultaten visar att team ofta tillämpar en selektiv och flexibel version av agila ramverk som

Air pollution severely impacts public health and contributes to diseases that affect good health-and well-being. This qualitative case study aims to evaluate how healthcare systems address-the disproportionate impacts of air pollution on low-income working communities in Delhi,-based on semi-structured interviews with NGOs, Think-Thanks and hospitals. Aspects of-healthcare access and the social de

This thesis explores how inclusive biodiversity governance can deliver socially and environmentally beneficial outcomes, focusing on the role of NGOs and CSOs in facilitating participation by local communities and Indigenous Peoples in Kenya. Drawing on qualitative interviews, project documents, and media content, the study explores what strategies are used to foster participation in a project by

This thesis explores the integration of generative AI in IT consultancy, focusing on how consultants and managers perceive its strategic and practical implications in project management. Using a dual-method approach, the study combines semi-structured interviews with AI-driven case experiments to investigate both human perspectives and AI performance. Findings reveal that generative AI is valued f

The use of picture storybooks has the potential to foster children’s environmental awareness and promote behavioural change, but little is known about their connection to the local context, particularly in Vietnam. This thesis presents a qualitative content analysis of sixteen children’s picture storybooks with environmental themes written by Vietnamese authors and illustrators, examining how they

In the face of a potential oncoming environmental collapse, in a time of increasing climate anxiety and activist disillusionment towards previous environmental efforts, I look at how a radical environmental activist group becomes and stays radical. By combining deviant and dramaturgical perspectives on social movements with Goffman’s classic work "The Presentation of Self in Everyday Life&quo