Missing observation analysis for matrix-variate time series data

Bayesian inference is developed for matrix-variate dynamic linear models (MV-DLMs), in order to allow missing observation analysis, of any sub-vector or sub-matrix of the observation time series matrix. We propose modifications of the inverted Wishart and matrix t distributions, replacing the scalar degrees of freedom by a diagonal matrix of degrees of freedom. The MV-DLM is then re-defined and modifications of the updating algorithm for missing observations are suggested

Forward particle production in proton-nucleus collisions at next-to-leading order

We consider the next-to-leading order (NLO) calculation of single inclusive particle production at forward rapidities in proton-nucleus collisions and in the framework of the Color Glass Condensate (CGC). We focus on the quark channel and the corrections associated with the impact factor. In the first step of the evolution the kinematics of the emitted gluon is kept exactly (and not in the eikonal approximation), but such a treatment which includes NLO corrections is not explicitly separated from the high energy evolution. Thus, in this newly established "factorization scheme", there is no "rapidity subtraction". The latter suffers from fine tuning issues and eventually leads to an unphysical (negative) cross section. On the contrary, our reorganization of the perturbation theory leads by definition to a well-defined cross section and the numerical evaluation of the NLO correction is shown to have the correct size.Comment: 7 pages, 5 figures, based on talk given at QCD@Work, 25-28 June 2018, Matera, Ital

Family and Landed Property Relations Regarded As a Social Capital

Putnam states that ‘the most fundamental form of social capital is the family.’ Bourdieu sees the family as the main site of accumulation and transmission of social capital, while Newton states that ‘the family may also be the most fundamental source of social capital.’ Social capital literature tends to emphasize the role of families in constructing social capital, be this within family networks or beyond in community networks. This paper aims at identifying ways to link exclusive forms of indigenous social capital such as land property, to more inclusive forms of social capital that integrate families and communities in a global process of development. This paper focuses on the role of family landed property in the creation of social networks leading to local development. The case study is of the Faliraki tourist community on the island of Rhodes, Greece. Available primary data refer to a 393-plot sample of cadastral histories and cover a 30-year period, from 1965 to 1995, when the transition from a rural area to an area established as tourist resort in the international market took place. A non-market transfer acts study (inheritances, donations and dowries) has revealed family property management practices and customary rules. One may observe a widespread phenomenon of social dispersion of land property amongst a great number of individuals and families, favoring the spontaneous creation of social networks on different levels and have supported – to a high degree – family businesses and local tourism development. Rather than viewing family businesses as rational decision-makers, the social capital approach of this paper suggests that family businesses and local development are embedded in social relations that influence their activities. Social capital may be the ‘missing link’ in development, as a complement and catalyst of the other, better-known species of capital.

JIMWLK evolution for multi-particle production with rapidity correlations

We study multi-particle production with rapidity correlations in proton-nucleus collisions at high energy in the Color Glass Condensate framework. The high-energy evolution responsible for such correlations is governed by a generalization of the JIMWLK equation describing the simultaneous evolution of the strong nuclear color fields in the direct amplitude and the complex conjugate amplitude. This functional equation can be used to derive ordinary evolution equations for the cross-sections for particle production, but the ensuing equations appear to be too complicated to be useful in practice, including in the limit of a large number of colors Nc. We propose an alternative formulation based on a Langevin process, which is valid for generic Nc and is better suited for numerical implementations. For illustration, we present the stochastic equations which govern two gluon production with arbitrary rapidity separation.Comment: 8 pages, 6 figures, based on talk given at IS 2013, 8 - 14 Sep 2013, Illa da Toxa, Spai