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Scale-invariant scalar field dark matter through the Higgs portal
Catarina Cosme
We introduce an oscillating scalar field coupled to the Higgs that can account for all dark matter in the Universe. Due to an underlying scale invariance of this model, the dark sc…
Can dark matter drive electroweak symmetry breaking?
Catarina Cosme, João G. Rosa, Orfeu Bertolami
We consider the possibility of an oscillating scalar field accounting for dark matter and dynamically controlling the spontaneous breaking of the electroweak symmetry through a Hig…
Scale-invariant scalar field dark matter through the Higgs portal
Catarina Cosme, João G. Rosa, O. Bertolami
We discuss the dynamics and phenomenology of an oscillating scalar field coupled to the Higgs boson that accounts for the dark matter in the Universe. The model assumes an underlyi…
Scalar field dark matter with spontaneous symmetry breaking and the keV line
Catarina Cosme, João G. Rosa, O. Bertolami
We show that the present dark matter abundance can be accounted for by an oscillating scalar field that acquires both mass and a non-zero expectation value from interactions with t…
Scalar field dark matter and the Higgs field
Orfeu Bertolami, Catarina Cosme, João G. Rosa
We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be o…
A Phase-Space Noncommutative Picture of Nuclear Matter
Orfeu Bertolami, Hodjat Mariji
Noncommutative features are introduced into a relativistic quantum field theory model of nuclear matter, the quantum hadrodynamics-I nuclear model (QHD-I). It is shown that the nuc…
Naturalness and stability of the generalized Chaplygin gas in the seesaw cosmon scenario
Alex E. Bernardini, O. Bertolami
The seesaw mechanism is conceived on the basis that a mass scale, , and a dimensionless scale, , can be fine-tuned in order to control the dynamics of active and sterile neut…
Constraints on unparticle long range forces from big bang nucleosynthesis bounds on the variation of the gravitational coupling
O. Bertolami, N. M. C. Santos
We use big bang nucleosynthesis bounds on the variation of the gravitational coupling to derive constraints on the strength of the deviation from the gravitational inverse-square l…
Coupling dark energy with Standard Model states
M. C. Bento, A. E. Bernardini, O. Bertolami
In this contribution one examines the coupling of dark energy to the gauge fields, to neutrinos, and to the Higgs field. In the first case, one shows how a putative evolution of th…
Stationary condition in a perturbative approach for mass varying neutrinos
Alex E. Bernardini, O. Bertolami
A perturbative approach for arbitrary choices of the equation of state of the universe is introduced in order to treat scenarios for mass varying neutrinos (MaVaN's) coupled to the…
Lorentz violating extension of the Standard Model and the Beta-decay end-point
Alex E. Bernardini, O. Bertolami
The Standard Model extension with additional Lorentz violating terms allows for redefining the equation of motion of a propagating left-handed fermionic particle. The obtained Dira…
The Higgs portal and an unified model for dark energy and dark matter
O. Bertolami, R. Rosenfeld
We examine a scenario where the Higgs boson is coupled to an additional singlet scalar field which we identify with a quintessence field. We show that this results in an unified pi…
Quantum and Classical divide: the gravitational case
O. Bertolami, J. G. Rosa
We study the transition between quantum and classical behavior of particles in a gravitational quantum well. We analyze how an increase in the particles mass turns the energy spect…
Bounds on Cubic Lorentz-Violating Terms in the Fermionic Dispersion Relation
O. Bertolami, J. G. Rosa
We study the recently proposed Lorentz-violating dispersion relation for fermions and show that it leads to two distinct cubic operators in the momentum. We compute the leading ord…
Threshold Effects and Lorentz Symmetry
Orfeu Bertolami
Evidence on the violation of Lorentz symmetry arises from the observation of cosmic rays with energies beyond the GZK cutoff, , from the apparen…
Topological Defect Densities in Type-I Superconducting Phase Transitions
J. Páramos, O. Bertolami, T. A. Girard +1
We examine the consequences of a cubic term addition to the mean-field potential of Ginzburg-Landau theory to describe first order superconductive phase transitions. Constraints on…
Ultracold neutrons, quantum effects of gravity and the Weak Equivalence Principle
O. Bertolami, F. M. Nunes
We consider an extension of the recent experiment with ultracold neutrons and the quantization of its vertical motion in order to test the Weak Equivalence Principle. We show that…
Cosmological Constraints on an Invisibly Decaying Higgs Boson
M. C. Bento, O. Bertolami, R. Rosenfeld
Working in the context of a proposal for collisional dark matter, we derive bounds on the Higgs boson coupling to a stable light scalar particle, which we refer to as…
Nucleosynthesis Constraints on a Scale-Dependent New Intermediate Range Interaction
O. Bertolami, F. M. Nunes
We derive constraints on the strength of a new intermediate range interaction that couples to baryon number from primordial nucleosynthesis yields. The nucleosysnthesis limits here…
CPT, Strings and Baryogenesis
O. Bertolami, D. Colladay, V. A. Kostelecký +1
In the context of string field theory, the possibility exists for the spontaneous violation of Lorentz invariance and CPT. In this talk, we review its status and some experimental…
CPT Violation and Baryogenesis
O. Bertolami, Don Colladay, V. Alan Kostelecký +1
We examine the effects on baryogenesis of spontaneous CPT violation in a string-based scenario. Under suitable circumstances, certain CPT-violating terms can produce a large baryon…
Phenomenological constraints on a scale-dependent gravitational coupling
Orfeu Bertolami, Juan García-Bellido
We investigate the astrophysical and cosmological implications of the recently proposed idea of a running gravitational coupling on macroscopic scales. We find that when applied to…