Physics / Fizik

Permanent URI for this collectionhttps://hdl.handle.net/11147/6

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Subject: search.filters.subject.Dark matterWoS Q: search.filters.wosQuartile.Q2

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Hidden Spin-3/2 Field in the Standard Model
    (Springer Verlag, 2017) Demir, Durmuş Ali; Karahan, Canan; Korutlu, Beste; Sargın, Ozan
    Here we show that a massive spin-3/2 field can hide in the SM spectrum in a way revealing itself only virtually. We study collider signatures and loop effects of this field, and determine its role in Higgs inflation and its potential as dark matter. We show that this spin-3/2 field has a rich linear collider phenomenology and motivates consideration of a neutrino–Higgs collider. We also show that the study of Higgs inflation, dark matter and dark energy can reveal more about the neutrino and dark sector. © 2017, The Author(s).
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Relativistic Mond From Modified Energetics
    (Springer Verlag, 2014) Demir, Durmuş Ali; Karahan, Canan Nurhan
    We begin to investigate the question of what modifications in the energy-momentum tensor can yield the correct MOND regime. As a starting study, we refrain from insisting on an action principle and focus exclusively on the equations of motion. The present work, despite the absence of an explicit action functional, can be regarded to extend Milgrom’s modified inertia approach to relativistic domain. Our results show that a proper MOND limit arises if the energy-momentum tensor is modified to involve the determinant of the metric tensor in reference to the flat metric, where the latter is dynamically generated as in the gravitational Higgs mechanism. This modified energy-momentum tensor is conserved in both Newtonian and MONDian regimes.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 19
    Scalars, Vectors and Tensors From Metric-Affine Gravity
    (Springer Verlag, 2013) Karahan, Canan Nurhan; Altaş, Aslı; Demir, Durmuş Ali
    The metric-affine gravity provides a useful framework for analyzing gravitational dynamics since it treats metric tensor and affine connection as fundamentally independent variables. In this work, we show that, a metric-affine gravity theory composed of the invariants formed from non-metricity, torsion and curvature tensors can be decomposed into a theory of scalar, vector and tensor fields. These fields are natural candidates for the ones needed by various cosmological and other phenomena. Indeed, we show that the model accommodates TeVeS gravity (relativistic modified gravity theory), vector inflation, and aether-like models. Detailed analyses of these and other phenomena can lead to a standard metric-affine gravity model encoding scalars, vectors and tensors.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Single Scale Factor for the Universe From the Creation of Radiation and Matter Till the Present
    (Springer Verlag, 2014) Erdem, Recai
    A scheme for incorporating the creation of radiation and matter into the cosmological evolution is introduced so that it becomes possible to merge the times before and after the creation of radiation and matter in a single scale factor in the Robertson–Walker metric. This scheme is illustrated through a toy model that has the prospect of constituting a basis for a realistic model.