26,966 research outputs found
A classical measure of evidence for general null hypotheses
In science, the most widespread statistical quantities are perhaps
-values. A typical advice is to reject the null hypothesis if the
corresponding p-value is sufficiently small (usually smaller than 0.05). Many
criticisms regarding p-values have arisen in the scientific literature. The
main issue is that in general optimal p-values (based on likelihood ratio
statistics) are not measures of evidence over the parameter space .
Here, we propose an \emph{objective} measure of evidence for very general null
hypotheses that satisfies logical requirements (i.e., operations on the subsets
of ) that are not met by p-values (e.g., it is a possibility measure).
We study the proposed measure in the light of the abstract belief calculus
formalism and we conclude that it can be used to establish objective states of
belief on the subsets of . Based on its properties, we strongly
recommend this measure as an additional summary of significance tests. At the
end of the paper we give a short listing of possible open problems.Comment: 26 pages, one figure and one table. Corrected versio
Two-loop self-energy diagrams worked out with NDIM
In this work we calculate two two-loop massless Feynman integrals pertaining
to self-energy diagrams using NDIM (Negative Dimensional Integration Method).
We show that the answer we get is 36-fold degenerate. We then consider special
cases of exponents for propagators and the outcoming results compared with
known ones obtained via traditional methods.Comment: LaTeX, 10 pages, 2 figures, styles include
Prescriptionless light-cone integrals
Perturbative quantum gauge field theory seen within the perspective of
physical gauge choices such as the light-cone entails the emergence of
troublesome poles of the type in the Feynman integrals,
and these come from the boson field propagator, where and
is the external arbitrary four-vector that defines the gauge proper.
This becomes an additional hurdle to overcome in the computation of Feynman
diagrams, since any graph containing internal boson lines will inevitably
produce integrands with denominators bearing the characteristic gauge-fixing
factor. How one deals with them has been the subject of research for over
decades, and several prescriptions have been suggested and tried in the course
of time, with failures and successes.
However, a more recent development in this front which applies the negative
dimensional technique to compute light-cone Feynman integrals shows that we can
altogether dispense with prescriptions to perform the calculations. An
additional bonus comes attached to this new technique in that not only it
renders the light-cone prescriptionless, but by the very nature of it, can also
dispense with decomposition formulas or partial fractioning tricks used in the
standard approach to separate pole products of the type , .
In this work we demonstrate how all this can be done.Comment: 6 pages, no figures, Revtex style, reference [2] correcte
Negative Dimensional Integration: "Lab Testing" at Two Loops
Negative dimensional integration method (NDIM) is a technique to deal with
D-dimensional Feynman loop integrals. Since most of the physical quantities in
perturbative Quantum Field Theory (pQFT) require the ability of solving them,
the quicker and easier the method to evaluate them the better. The NDIM is a
novel and promising technique, ipso facto requiring that we put it to test in
different contexts and situations and compare the results it yields with those
that we already know by other well-established methods. It is in this
perspective that we consider here the calculation of an on-shell two-loop three
point function in a massless theory. Surprisingly this approach provides twelve
non-trivial results in terms of double power series. More astonishing than this
is the fact that we can show these twelve solutions to be different
representations for the same well-known single result obtained via other
methods. It really comes to us as a surprise that the solution for the
particular integral we are dealing with is twelvefold degenerate.Comment: 10 pages, LaTeX2e, uses style jhep.cls (included
Maximum Entropy Principle and the Higgs Boson Mass
A successful connection between Higgs boson decays and the Maximum Entropy
Principle is presented. Based on the information theory inference approach we
determine the Higgs boson mass as GeV, a value fully
compatible to the LHC measurement. This is straightforwardly obtained by taking
the Higgs boson branching ratios as the target probability distributions of the
inference, without any extra assumptions beyond the Standard Model. Yet, the
principle can be a powerful tool in the construction of any model affecting the
Higgs sector. We give, as an example, the case where the Higgs boson has an
extra invisible decay channel. Our findings suggest that a system of Higgs
bosons undergoing a collective decay to Standard Model particles is among the
most fundamental ones where the Maximum Entropy Principle applies.Comment: Version published in Physica
Genus Two Partition Functions and Renyi Entropies of Large c CFTs
We compute genus two partition functions in two dimensional conformal field
theories at large central charge, focusing on surfaces that give the third
Renyi entropy of two intervals. We compute this for generalized free theories
and for symmetric orbifolds, and compare it to the result in pure gravity. We
find a new phase transition if the theory contains a light operator of
dimension . This means in particular that unlike the second
Renyi entropy, the third one is no longer universal.Comment: 28 pages + Appendice
Inferences on the Higgs Boson and Axion Masses through a Maximum Entropy Principle
The Maximum Entropy Principle (MEP) is a method that can be used to infer the
value of an unknown quantity in a set of probability functions. In this work we
review two applications of MEP: one giving a precise inference of the Higgs
boson mass value; and the other one allowing to infer the mass of the axion. In
particular, for the axion we assume that it has a decay channel into pairs of
neutrinos, in addition to the decay into two photons. The Shannon entropy
associated to an initial ensemble of axions decaying into photons and neutrinos
is then built for maximization.Comment: Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs,
Thessaloniki, May 15 to 19, 201
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