3,442 research outputs found
On Detecting Discrete Cheshire Charge
We analyze the charges carried by loops of string in models with non-abelian
local discrete symmetry. The charge on a loop has no localized source, but can
be detected by means of the Aharonov--Bohm interaction of the loop with another
string. We describe the process of charge detection, and the transfer of charge
between point particles and string loops, in terms of gauge--invariant
correlation functions.Comment: (17 pp
Complementarity in Wormhole Chromodynamics
The electric charge of a wormhole mouth and the magnetic flux ``linked'' by
the wormhole are non-commuting observables, and so cannot be simultaneously
diagonalized. We use this observation to resolve some puzzles in wormhole
electrodynamics and chromodynamics. Specifically, we analyze the color electric
field that results when a colored object traverses a wormhole, and we discuss
the measurement of the wormhole charge and flux using Aharonov-Bohm
interference effects. We suggest that wormhole mouths may obey conventional
quantum statistics, contrary to a recent proposal by Strominger.Comment: 12 pages and 2 figures, phyzzx, CALT-68-188
Wealth Effects of Dividend Announcements on Bondholders: The Case of Taiwan Bond Market
Although bonds play an important role in U.S. capital markets, this financial instrument is less common in the emerging markets. Taiwan is a typical case. In fact, both bond issuances and bond transactions in Taiwan have been declining in the past years. Consistent with the previous studies, this research documents that wealth transfer effects exist between bondholders and stockholders. We hypothesize that this wealth transfer discourages investors from investing in bond markets because companies in Taiwan seem to care less about the interest of bondholders. Using the event study methodology, we examine the price change of bonds and stocks in Taiwan capital market around cash dividend announcements. We find that there are significant abnormal returns before cash dividend announcements from 30 days to 60 days and that there is insignificant price change of bonds during the three-day period around the announcement. Possible explanations of the results include low bond trading volumes, insider trading before announcements, and mixing signaling and wealth transfer effects. Although this study cannot prove that the results are directly related to management holdings, we tend to believe that insider trading somehow matters
Tailorable polymer waveguides for miniaturized bio-photonic devices via two-polymer microtransfer molding
Traditional optical fibers have been developed to achieve novel characteristics for both macro- and micro-applications. Inorganic optical waveguides using two-dimensional photonic crystals and silicon-on-insulator technology are examples of recent trends for macro- and micro-scale optical applications, respectively. As bio-photonics devices operate mostly with visible light, visible-transparent materials such as metal oxides and polymers are preferred as the guiding medium. Although polymers have tremendous potential because of their enormous variation in optical, chemical and mechanical properties, their application for optical waveguides is limited by conventional lithography. We present a non-optical lithographic technique, called two-polymer microtransfer molding, to fabricate polymer nano-waveguides, on-chip light sources and couplers. Micro-sources using quantum dots emitting red light (625nm) are successfully embedded in a waveguides array as the on-chip light sources. Fabrication of a grating coupler is also attempted for various external light sources including lasers and white light. We have quantified propagation losses of the waveguides using CCD photometry. The guiding loss is approximately 1.7dB/mm. We also demonstrated that the surface roughness of the fabricated waveguides can be reduced by chemical etching. We demonstrate that low cost, high yield, high fidelity, and tailorable fabrication of bio-photonic devices are achievable by the combination of the presented techniques
An Exploration of In-Context Learning for Speech Language Model
Ever since the development of GPT-3 in the natural language processing (NLP)
field, in-context learning (ICL) has played an important role in utilizing
large language models (LLMs). By presenting the LM utterance-label
demonstrations at the input, the LM can accomplish few-shot learning without
relying on gradient descent or requiring explicit modification of its
parameters. This enables the LM to learn and adapt in a black-box manner.
Despite the success of ICL in NLP, little work is exploring the possibility of
ICL in speech processing. This study proposes the first exploration of ICL with
a speech LM without text supervision. We first show that the current speech LM
does not have the ICL capability. With the proposed warmup training, the speech
LM can, therefore, perform ICL on unseen tasks. In this work, we verify the
feasibility of ICL for speech LM on speech classification tasks.Comment: The first two authors contributed equall
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