Supergauge interactions and electroweak baryogenesis (2009)
Chung, Daniel J. H., Garbrecht, Bjorn, Ramsey-Musolf, Michael. J., Tulin, Sean
We present a complete treatment of the diffusion processes for supersymmetric electroweak baryogenesis that characterizes transport dynamics ahead of the phase transition bubble wall within the...
Lepton-mediated electroweak baryogenesis (2009)
Chung, Daniel J. H., Garbrecht, Bjorn, Ramsey-Musolf, Michael J., Tulin, Sean
We investigate the impact of the tau and bottom Yukawa couplings on the transport dynamics for electroweak baryogenesis in supersymmetric extensions of the Standard Model. Although it has generally...
Low Scale Leptogenesis from Non-Leptonic CP-Phases (2009)
Chung, Daniel J. H., Garbrecht, Bjorn, Ramsey-Musolf, Michael J.
This paper has been withdrawn by the authors.
Separation of Equilibration Time-Scales in the Gradient Expansion (2008)
Garbrecht, Bjorn, Konstandin, Thomas
We study thermalization by applying gradient expansion to the Kadanoff-Baym equations of the 2PI effective action to one-loop in a theory with Dirac fermions coupled to scalars. In addition to those...
Yukawa Interactions and Supersymmetric Electroweak Baryogenesis (2008)
Chung, Daniel J. H., Garbrecht, Bjorn, Ramsey-Musolf, Michael J., Tulin, Sean
We analyze the quantum transport equations for supersymmetric electroweak baryogenesis including previously neglected bottom and tau Yukawa interactions and show that they imply the presence of a...
The Effect of the Sparticle Mass Spectrum on the Conversion of B-L to B (2008)
Chung, Daniel J H, Garbrecht, Bjorn, Tulin, Sean
In the context of many leptogenesis and baryogenesis scenarios, B-L (baryon minus the lepton number) is converted into B (baryon number) by non-perturbative B+L violating operators in the SU(2)_L...
Textures and Semi-Local Strings in SUSY Hybrid Inflation (2008)
Battye, Richard A., Garbrecht, Bjorn, Pilaftsis, Apostolos
Global topological defects may account for the large cold spot observed in the Cosmic Microwave Background. We explore possibilities of constructing models of supersymmetric F-term hybrid inflation,...
Constraints on Brane Inflation and Cosmic Strings (2007)
Battye, Richard A., Garbrecht, Bjorn, Moss, Adam, Stoica, Horace
By considering simple, but representative, models of brane inflation from a single brane-antibrane pair in the slow roll regime, we provide constraints on the parameters of the theory imposed by...
Baryogenesis from the amplification of vacuum fluctuations during inflation (2007)
Garbrecht, Bjorn, Prokopec, Tomislav
We propose that the baryon asymmetry of the Universe may originate from the amplification of quantum fluctuations of a light complex scalar field during inflation. CP-violation is sourced by complex...
Radiative Lifting of Flat Directions of the MSSM in de Sitter Background (2006)
The one-loop effective potential for a charged scalar field in de Sitter background is studied. We derive an approximate form for the gauge boson propagator with a general covariant gauge-fixing...
Hybrid Inflation Exit through Tunneling (2006)
Garbrecht, Bjorn, Konstandin, Thomas
For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling...
Constraints on Supersymmetric Models of Hybrid Inflation (2006)
Battye, Richard A., Garbrecht, Bjorn, Moss, Adam
We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density...
Anatomy of F_D-Term Hybrid Inflation (2006)
Garbrecht, Bjorn, Pallis, Constantinos, Pilaftsis, Apostolos
We analyze the cosmological implications of F-term hybrid inflation with a subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a D-parity in the inflaton-waterfall sector. This...
Ultraviolet Regularisation in de Sitter Space (2006)
The ultraviolet regularisation of Yukawa theory in de Sitter space is considered. We rederive the one-loop effective Candelas-Raine potentials, such that they agree with the corresponding...
Perturbative and Nonperturbative Contributions to a Simple Model for Baryogenesis (2006)
Balaji, K. R. S., Garbrecht, Bjorn
Single field baryogenesis, a scenario for Dirac leptogenesis sourced by a time-dependent scalar condensate, is studied. We compare the creation of the charge asymmetry by the perturbative decay of...
Fermion Mass Generation in de Sitter Space (2006)
Garbrecht, Bjorn, Prokopec, Tomislav
We study the one-loop radiative corrections for massless fermions in de Sitter space induced by a Yukawa coupling to a light, nearly minimally coupled scalar field. We show that the fermions acquire...
F_D-Term Hybrid Inflation with Electroweak-Scale Lepton Number Violation (2006)
Garbrecht, Bjorn, Pilaftsis, Apostolos
We study F-term hybrid inflation in a novel supersymmetric extension of the SM with a subdominant Fayet-Iliopoulos D-term. We call this particular form of inflation, in short, F_D-term hybrid...
Lamb Shift of Unruh Detector Levels (2005)
Garbrecht, Bjorn, Prokopec, Tomislav
We argue that the energy levels of an Unruh detector experience an effect similar to the Lamb shift in Quantum Electrodynamics. As a consequence, the spectrum of energy levels in a curved background...
SO(10)-GUT Coherent Baryogenesis (2005)
Garbrecht, Bjorn, Prokopec, Tomislav, Schmidt, Michael G.
A model for GUT baryogenesis, coherent baryogenesis within the framework of supersymmetric SO(10), is considered. In particular, we discuss the Barr-Raby model, where at the end of hybrid infl ation...
Coherent Baryogenesis and Nonthermal Leptogenesis: A comparison (2004)
Garbrecht, Bjorn, Prokopec, Tomislav, Schmidt, Michael G.
We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a varying mass by their coupling to a time dependent field. Their CP-violating mass matrix can generate a...
Energy Density in Expanding Universes as Seen by Unruh's Detector (2004)
Garbrecht, Bjorn, Prokopec, Tomislav
We consider the response of an Unruh detector to scalar fields in an expanding space-time. When combining transition elements of the scalar field Hamiltonian with the interaction operator of detector...
Unruh response functions for scalar fields in de Sitter space (2004)
Garbrecht, Bjorn, Prokopec, Tomislav
We calculate the response functions of a freely falling Unruh detector in de Sitter space coupled to scalar fields of different coupling to the curvature, including the minimally coupled massless...
Garbrecht, Bjorn, Prokopec, Tomislav, Schmidt, Michael G.
We propose a new baryogenesis scenario based on coherent production and mixing of different fermionic species. The mechanism is operative during phase transitions, at which the fermions acquire...
Particle number in kinetic theory (2002)
Garbrecht, Bjorn, Prokopec, Tomislav, Schmidt, Michael G.
We provide a derivation for the particle number densities on phase space for scalar and fermionic fields in terms of Wigner functions. Our expressions satisfy the desired properties: for bosons the...