254 research outputs found
Construction of an Identically Nilpotent BRS Charge in the Kato-Ogawa String Theory
In previous work, the conformal-gauge two-dimensional quantum gravity in the
BRS formalism has been solved completely in terms of Wightman functions. In the
present paper, this result is extended to the closed and open bosonic strings
of finite length; the open-string case is nothing but the Kato-Ogawa string
theory. The field-equation anomaly found previously, which means a slight
violation of a field equation at the level of Wightman functions, remains
existent also in the finite-string cases. By using this fact, a BRS charge
nilpotent even for is explicitly constructed in the framework of the
Kato-Ogawa string theory. The FP-ghost vacuum structure of the Kato-Ogawa
theory is made more transparent; the appearance of half-integral ghost numbers
and the artificial introduction of indefinite metric are avoided.Comment: 23 pages, LaTe
Anomaly Problem in a Simple Model Analogous to the Lightcone-Gauge Two-Dimensional Quantum Gravity
It was found in the two-dimensional quantum gravity both in the de Donder
gauge and in the lightcone gauge that one of field equations breaks down at the
level of the representation, though the breakdown is very little. It is shown
that this anomalous behavior occurs also in a very simple model analogous to
the lightcone-gauge two-dimensional quantum gravity. This model, however, can
be transformed into a free field theory by a nonsingular transformation. Of
course, the latter has no anomaly. The cause of the discrepancy is analyzed.Comment: 16 pages, LaTeX, overcite.st
Proof of the Gauge Independence of the Conformal Anomaly of Bosonic String in the Sense of Kraemmer and Rebhan
Kraemmer and Rebhan claimed the gauge independence of the conformal anomaly
of bosonic string for various gauge fixings in the framework of the
perturbation theory of two-dimensional quantum gravity. It is pointed out that
their proof is wrong. The gauge independence is proved for the gauge-fixings
which reduce to the linearized de Donder gauge in the flat limit of the
background metric. Similar remarks are made also for the Rebhan-Kraemmer
current anomaly.Comment: 14 pages, LaTeX, two stylefiles include
Perturbative or Path-Integral Approach versus Operator-Formalism Approach
In the conformal-gauge two-dimensional quantum gravity, the solution obtained
by the perturbative or path-integral approach is compared with the one obtained
by the operator-formalism approach. Treatments of the anomaly problem in both
approaches are different. This difference is found to be essentially caused by
the fact that the perturbative or path-integral approach is based on the
T*-product (covariantized T-product), which generally violates field equations.
Indeed, this fact induces some extra one-loop Feynman diagrams, which would not
exist unless a nonzero contribution arose from a zero field. Some demerits of
the path-integral approach are explicitly demonstrated.Comment: 16 pages, PTPTe
Exact Solutions to the Two-dimensional BF and Yang-Mills Theories in the Light-cone Gauge
It is shown that the BRS-formulated two-dimensional BF theory in the
light-cone gauge (coupled with chiral Dirac fields) is solved very easily in
the Heisenberg picture. The structure of the exact solution is very similar to
that of the BRS-formulated two-dimensional quantum gravity in the conformal
gauge. In particular, the BRS Noether charge has anomaly. Based on this fact, a
criticism is made on the reasoning of Kato and Ogawa, who derived the critical
dimension D=26 of string theory on the basis of the anomaly of the BRS Noether
charge. By adding the term to the BF-theory Lagrangian
density, the exact solution to the two-dimensional Yang-Mills theory is also
obtained.Comment: 11 pages, LaTe
D=26 and Exact Solution to the Conformal-Gauge Two-Dimensional Quantum Gravity
The conformal-gauge two-dimensional quantum gravity is formulated in the
framework of the BRS quantization and solved completely in the Heisenberg
picture: All n-point Wightman functions are explicitly obtained. The
field-equation anomaly is shown to exist as in other gauges, but there is no
other subtlety. At the critical dimension D=26 of the bosonic string, the
field-equation anomaly is shown to be absent. However, this result is not
equivalent to the statement that the conformal anomaly is proportional to D-26.
The existence of the FP-ghost number current anomaly is seen to be an illusion.Comment: 18 pages, LaTe
Sound collection and visualization system enabled participatory and opportunistic sensing approaches
This paper presents a sound collection system to
visualize environmental sounds that are collected using a crowd-sourcing approach. An analysis of physical features is generally used to analyze sound properties; however, human beings not
only analyze but also emotionally connect to sounds. If we want to visualize the sounds according to the characteristics of the listener,
we need to collect not only the raw sound, but also the subjective feelings associated with them. For this purpose, we developed a sound collection system using a crowdsourcing approach to collect physical sounds, their statistics, and subjective evaluations simultaneously. We then conducted a sound collection experiment using the developed system on ten participants.We collected 6,257 samples of equivalent loudness levels and their locations, and 516 samples of sounds and their locations. Subjective evaluations by
the participants are also included in the data. Next, we tried to visualize the sound on a map. The loudness levels are visualized as a color map and the sounds are visualized as icons which
indicate the sound type. Finally, we conducted a discrimination experiment on the sound to implement a function of automatic conversion from sounds to appropriate icons. The classifier is
trained on the basis of the GMM-UBM (Gaussian Mixture Model and Universal Background Model) method. Experimental results show that the F-measure is 0.52 and the AUC is 0.79
- …