Large amplitude coherent state superposition generated by a time-separated two-photon subtraction from a continuous wave squeezed vacuum

Theoretical analysis is given for a two-photon subtraction from a continuous wave (CW) squeezed vacuum with finite time separation between two detection events. In the CW photon subtraction process, the generated states are inevitably described by temporal mutimode states. Our approach is based on Schr\"{o}dinger picture which provides mathematically simple forms and an intuitive understanding of its multimode structure. We show that, in our process, the photon subtracted squeezed vacuum is generated in two temporal modes and one of these modes acts as an ancillary mode to make the other one a large amplitude coherent state superposition.Comment: 9 pages, 8 figure

Temporally multiplexed superposition states of continuous variables

We study non-Gaussian states generated by two-photon subtraction from a cw squeezed light source. In a cw scheme one can subtract two photons from the source with a designated time separation and can genarate temporally multiplexed superposition states of continuous variables. We numerically study the properties of these states in the light of bosonic interference in the time domain. In an appropriate temporal mode amplified kittens are produced in a region where the time separation is comparable with the correlation time of squeezed packets.Comment: 12 pages, 10 figure

Cohomology Algebras of Blocks of Finite Groups and Brauer Correspondence II

Let k be an algebraically closed field of characteristic p. We shall discuss the cohomology algebras of a block ideal B of the group algebra kG of a finite group G and a block ideal C of the block ideal of kH of a subgroup H of G which are in Brauer correspondence and have a common defect group, continuing (Kawai and Sasaki, Algebr Represent Theory 9(5):497-511, 2006). We shall define a (B,C)-bimodule L. The k-dual L (*) induces the transfer map between the Hochschild cohomology algebras of B and C, which restricts to the inclusion map of the cohomology algebras of B into that of C under some condition. Moreover the module L induces a kind of refinement of Green correspondence between indecomposable modules lying in the blocks B and C; the block varieties of modules lying in B and C which are in Green correspondence will also be discussed.ArticleALGEBRAS AND REPRESENTATION THEORY. 13(4):445-465 (2010)journal articl

Relationships between Agricultural policies and Environmental Effects in Japan: An Environmental-Economic Integrated Model Approach

This study investigates the optimal agricultural land use allocation and nitrogen application to a representative Japanese farm. The site-specific nature of numerous agri-environmental issues necessitates analysis at a disaggregated level in order to capture the underlying heterogeneity of agricultural productivity and environmental sensitivity across different parcels of land. This study adopts an integrated approach—a decision-making economic model for representative farms is combined with a stylized site-specific biophysical model, which quantifies the impact of different policy instruments on agricultural production practices and on multiple environmental effects. This model estimates the government budget outlays and social welfare, which require monetary valuation of environmental effects as well as of crop production. In addition to several agri-environmental policy scenarios, this study investigates the impact of the rice production adjustment policy, wherein a rice production quota is allocated to each region on the basis of the sales records for the previous two years. According to the simulation results, there is greater increase in social welfare when farmers are paid in order to reduce chemical fertilizer applications rather than by levying a nitrogen tax. Regarding carbon sequestration, the modelling exercise indicates that an agrienvironmental payment depending on the level of application of organic fertilizer (manure) is preferable; however, the social welfare derived by payments on the basis of the application of a minimum organic matter, which may avoid increasing the fiscal budget burden (on account of the increased application of organic matter on paddy fields), is higher than that derived by unit payments depending on the level of application of organic matter. The relaxation of the rice production quota results in an increase in social welfare. This integrated model approach is subject to limitations with respect to the data, model parameters, as well as economic and biophysical relationships. However, this approach is a valuable tool for enabling policy makers to design and implement effective and efficient policies.integrate model, agri-environmental policy, paddy field, production quota, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Land Economics/Use, Production Economics, Productivity Analysis,

Agri-environmental Policies and their Impacts on the Environment and Different Farm Types in Japan: An Economic-Biophysical Model Approach

Promoting environmentally friendly farming products is crucial to meeting consumer demand. Although governments implement policy measures to improve the environmental performance of the agriculture sector, their impacts are difficult to assess. This study analyses the performance of agri-environmental policies in Japan, by using the OECD’s policy impact model and reference level framework. In particular, it identifies the environmental impacts of three simulated agri-environmental policies based on farms’ characteristics. The results suggest that a policy mix of regulation and an incentive payment would reduce environmental impacts, suggesting that targeted approaches could improve the cost-effectiveness of agri-environmental policies

Agri‐environmental Policies to Meet Consumer Preferences in Japan: An Economic‐Biophysical Model Approach

Promoting environmentally friendly farming products is crucial to meeting consumer demand. Although governments implement policy measures to improve the environmental performance of the agriculture sector, theirimpacts are difficult to assess. This study analyses the performance of agri‐environmental policies in Japan, by using the OECD’s policy impact model and reference level framework. In particular, it identifies the environmental impacts of three simulated agri‐environmental policies based on farms’ characteristics. The results suggest that a policy mix of regulation and an incentive payment would reduce environmental impacts, suggesting that targeted approaches could improve the cost‐effectiveness of agri‐environmental policies

Conservation Auctions and Compliance: Theory and Evidence from Laboratory Experiments

Poster prepared for presentation at the Agricultural & Applied Economics Association 2010 AAEA,CAES, & WAEA Joint Annual Meeting, Denver, Colorado, July 25-27, 2010.Auctions, Conservation contracting, Compliance, Environmental Economics and Policy, C91, D44, Q24,

Von K\'arm\'an vortex street in a Bose-Einstein condensate

Vortex shedding from an obstacle potential moving in a Bose-Einstein condensate is investigated. Long-lived alternately aligned vortex pairs are found to form in the wake, as for the von K\'arm\'an vortex street in classical viscous fluids. Various patterns of vortex shedding are systematically studied and the drag force on the obstacle is calculated. It is shown that the phenomenon can be observed in a trapped system.Comment: 4 pages, 5 figure