298,910 research outputs found
Restricted Value Iteration: Theory and Algorithms
Value iteration is a popular algorithm for finding near optimal policies for
POMDPs. It is inefficient due to the need to account for the entire belief
space, which necessitates the solution of large numbers of linear programs. In
this paper, we study value iteration restricted to belief subsets. We show
that, together with properly chosen belief subsets, restricted value iteration
yields near-optimal policies and we give a condition for determining whether a
given belief subset would bring about savings in space and time. We also apply
restricted value iteration to two interesting classes of POMDPs, namely
informative POMDPs and near-discernible POMDPs
Pointed Hopf Algebras with classical Weyl Groups
We prove that Nichols algebras of irreducible Yetter-Drinfeld modules over
classical Weyl groups supported by are
infinite dimensional, except in three cases. We give necessary and sufficient
conditions for Nichols algebras of Yetter-Drinfeld modules over classical Weyl
groups supported by to be finite dimensional.Comment: Combined with arXiv:0902.4748 plus substantial changes. To appear
International Journal of Mathematic
LHC Accessible Second Higgs Boson in the Left-Right Model
A second Higgs doublet arises naturally as a parity partner of the standard
model (SM) Higgs, once SM is extended to its left-right symmetric version
(LRSM) to understand the origin of parity violation in weak interactions as
well as to accommodate small neutrino masses via the seesaw mechanism. The
flavor changing neutral Higgs (FCNH) effects in the minimal version of this
model (LRSM), however, push the second Higgs mass to more than 15 TeV making it
inaccessible at the LHC. Furthermore since the second Higgs mass is directly
linked to the mass, discovery of a "low" mass (
TeV) at the LHC would require values for some Higgs self couplings larger than
one. In this paper we present an extension of LRSM by adding a vector-like
quark doublet which weakens the FCNH constraints allowing the second
Higgs mass to be near or below TeV and a third neutral Higgs below 3 TeV for a
mass below 5 TeV. It is then possible to search for these heavier Higgs
bosons at the LHC, without conflicting with FCNH constraints. A right handed
mass in the few TeV range is quite natural in this class of models
without having to resort to large scalar coupling parameters. The CKM mixings
are intimately linked to the vector-like quark mixings with the known quarks,
which is the main reason why the constraints on the second Higgs mass is
relaxed. We present a detailed theoretical and phenomenological analysis of
this extended LR model and point out some tests as well as its potential for
discovery of a second Higgs at the LHC. Two additional features of the model
are: (i) a 5/3 charged quark and (ii) a fermionic top partner with masses in
the TeV range.Comment: 22 pages, 4 figures, lots of stuff moved to the appendices, errors
and typos corrected, version to appear in PR
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