14,718 research outputs found

### Update on the Pyramid Scheme

We summarize recent work in which we attempt to make a consistent model of
LHC physics, from the Pyramid Scheme. The models share much with the NMSSM, in
particular, enhanced tree level contributions to the Higgs mass and a
preference for small tan {\beta}. There are 3 different singlet fields, and a
new strongly coupled gauge theory, so the constraints of perturbative
unification are quite different. We outline our general approach to the model,
which contains a Kahler potential for three of the low energy fields, which is
hard to calculate. Detailed calculations, based on approximations to the Kahler
potential, will be presented in a future publication.Comment: LaTeX 2e/ 9 page

### Regulating Eternal Inflation II: The Great Divide

In a previous paper, two of the authors presented a "regulated" picture of
eternal inflation. This picture both suggested and drew support from a
conjectured discontinuity in the amplitude for tunneling from positive to
negative vacuum energy, as the positive vacuum energy was sent to zero;
analytic and numerical arguments supporting this conjecture were given. Here we
show that this conjecture is false, but in an interesting way. There are no
cases where tunneling amplitudes are discontinuous at vanishing cosmological
constant; rather, the space of potentials separates into two regions. In one
region decay is strongly suppressed, and the proposed picture of eternal
inflation remains viable; sending the (false) vacuum energy to zero in this
region results in an absolutely stable asymptotically flat space. In the other
region, we argue that the space-time at vanishing cosmological constant is
unstable, but not asymptotically Minkowski. The consequences of our results for
theories of supersymmetry breaking are unchanged.Comment: JHEP3, 19 Pages, 7 Figure

### Towards a quantum theory of de Sitter space

We describe progress towards constructing a quantum theory of de Sitter space
in four dimensions. In particular we indicate how both particle states and
Schwarzschild de Sitter black holes can arise as excitations in a theory of a
finite number of fermionic oscillators. The results about particle states
depend on a conjecture about algebras of Grassmann variables, which we state,
but do not prove.Comment: JHEP3 LaTex - 19 page

### Embedding the Pentagon

The Pentagon Model is an explicit supersymmetric extension of the Standard
Model, which involves a new strongly-interacting SU(5) gauge theory at
TeV-scale energies. We show that the Pentagon can be embedded into an SU(5) x
SU(5) x SU(5) gauge group at the GUT scale. The doublet-triplet splitting
problem, and proton decay compatible with experimental bounds, can be
successfully addressed in this context. The simplest approach fails to provide
masses for the lighter two generations of quarks and leptons; however, this
problem can be solved by the addition of a pair of antisymmetric tensor fields
and an axion.Comment: 39 page

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