Essays about: "invariance"

Showing result 1 - 5 of 48 essays containing the word invariance.

  1. 1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity

    University essay from KTH/Fysik

    Author : Atabak Fathe Jalali; [2024]
    Keywords : Theoretical physics; astrophysics; modified gravity; minimally modified gravity; gravitational collapse; VCDM; scalar collapse; apparent horizon; numerical relativity; Teoretisk fysik; astrofysik; modifierad gravitation; minimalt modifierad gravitation; gravitationskollaps; VCDM; skalär kollaps; uppenbar horisont; numerisk relativitet;

    Abstract : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. READ MORE

  3. 2. Exploring electroweak symmetry breaking in the scale-invariant Two-Higgs-Doublet Model

    University essay from Lunds universitet/Fysiska institutionen; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Erik Rustas; [2023]
    Keywords : Two-Higgs-Doublet Models; 2HDM; Scale-invariance; Baryogenesis; BSM; Baryon Asymmetry; Coleman-Weinberg Potential; Theoretical Particle Physics; Physics and Astronomy;

    Abstract : This thesis investigates the properties of a general scale-invariant Two-Higgs-Doublet Model and its phenomenological consequences with focus on the scalar sector. The concept suggests that introducing more CP-violation, both spontaneous and explicit, may make it possible to meet the Sakharov conditions and account for the Universe's baryon asymmetry. READ MORE

  4. 3. On Linear Mode Connectivity up to Permutation of Hidden Neurons in Neural Network : When does Weight Averaging work?

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Adhithyan Kalaivanan; [2023]
    Keywords : Mode Connectivity; Representation Learning; Loss Landscape; Network Symmetry; Lägesanslutning; representationsinlärning; förlustlandskap; nätverkssymmetri;

    Abstract : Neural networks trained using gradient-based optimization methods exhibit a surprising phenomenon known as mode connectivity, where two independently trained network weights are not isolated low loss minima in the parameter space. Instead, they can be connected by simple curves along which the loss remains low. READ MORE

  5. 4. Machine Learning for Pulse Shape Analysis of Heavy Ions

    University essay from Uppsala universitet/Tillämpad kärnfysik

    Author : Steven Hendrik Bijl; [2023]
    Keywords : Heavy Ions; Machine Learning;

    Abstract : Most of the Generation IV nuclear reactors designs are intended to operate with a fast neutron spectrum. This necessitates further investigation into nuclear fuel behaviour because fast neutrons yield a higher neutron multiplicity with fission fragments, significantly impacting the criticality assessment of these reactors. READ MORE

  6. 5. On the Equivalence of Time-Varying CBF-Based Control and Prescribed Performance Control : Conversion and Qualitative Comparison

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Ryo Namerikawa; [2023]
    Keywords : Control Barrier Function; Invariance control; Nonlinear control; Prescribed Performance Control; Safety-critical system; Icke-linjär reglering; invariansreglering; säkerhetskritiska system; prestandasäkring;

    Abstract : These days, a wide range of autonomous systems, such as automobiles, delivery drones, and embedded household systems, are becoming more and more common in our society. This trend is projected to continue in the future. To effectively manage these dynamic systems, ensuring their safe operation is crucial for the well-being of our lives. READ MORE