8,767 research outputs found
Full counting statistics of weak measurement
A weak measurement consists in coupling a system to a probe in such a way
that constructive interference generates a large output. So far, only the
average output of the probe and its variance were studied. Here, the
characteristic function for the moments of the output is provided. The outputs
considered are not limited to the eigenstates of the pointer or of its
conjugate variable, so that the results apply to any observable \Hat{o} of
the probe. Furthermore, a family of well behaved complex quantities, the normal
weak values, is introduced, in terms of which the statistics of the weak
measurement can be described. It is shown that, within a good approximation,
the whole statistics of weak measurement is described by a complex parameter,
the weak value, and a real one.Comment: Expanded version: 9 pages, 3 Figs. Now the validity of the expansion
for the moments is analysed. Introduced a one-parameter family of weak
values, useful to express the correct characteristic function. More figures
added. Thanks to Referee C of PRL for asking stimulating question
Methodological problems in solvency assessment of an insurance company
The recent wide development and changes in insurance markets highlighted the necessity to map out the solvency analysis in a more complete framework. The approach we present in the paper comes up with an integrated analysis of the risk profile of an insurance business, taking into account the actual European directives about solvency assessment. The aim of the paper is to construct a methodology apt to incorporate properly the effect of the risk sources in calculating mathematical provisions related to a portfolio of insurance policies.Life insurance, financial risk, demographic risk, capital adequacy, reserves, conditional random processes
Sequential measurement of conjugate variables as an alternative quantum state tomography
It is shown how it is possible to reconstruct the initial state of a
one-dimensional system by measuring sequentially two conjugate variables. The
procedure relies on the quasi-characteristic function, the Fourier-transform of
the Wigner quasi-probability. The proper characteristic function obtained by
Fourier-transforming the experimentally accessible joint probability of
observing "position" then "momentum" (or vice versa) can be expressed as a
product of the quasi-characteristic function of the two detectors and that,
unknown, of the quantum system. This allows state reconstruction through the
sequence: data collection, Fourier-transform, algebraic operation, inverse
Fourier-transform. The strength of the measurement should be intermediate for
the procedure to work.Comment: v2, 5 pages, no figures, substantial improvements in the
presentation, thanks to an anonymous referee. v3, close to published versio
Recommended from our members
Pension schemes versus real estate
The demographic, economic and social changes that have characterized the last decades, and the dramatic financial crisis that has taken place since 2008, have led to a demand for structural changes in the pension sector and a growing interest in individual pension products. Hence the need, for most elderly people, to liquidate their fixed assets, which are usually the homes in which they live. This highlights products such as reverse mortgages and domestic reversibility plans. Within this context, we propose a contractual scheme where an immediate life annuity is obtained by paying a single-premium in the form of real estate rights (RERs), for example by transferring to an insurer the property title of a house or a similar realty, while keeping its usufruct or a restricted bundle of rights. The level of the installments depends on the fair value of the transferred RER at the contract’s issue, the life expectancy of the insured and the expected growth rate of the real estate market value. The contract design is developed by considering the control of the financial risk inherent in the contract itself, because of the prospective changes in the value of the RERs, and the level of the insurer’s leverage. Finally, we provide some numerical evidence of the proposed contractual structure, in order to compare the level of the installments according to the house return forecasts in different European countries
Separating the North and South Pacific Meridional Modes Contributions to ENSO and Tropical Decadal Variability
North and South Pacific Meridional Modes (NPMM and SPMM) are known precursors of El Niño–Southern Oscillation (ENSO) and Tropical Pacific decadal variability (TPDV). However, the relative importance of these precursors and the timescale on which they impact the tropics remain unclear. Using a 30-member ensemble of the Community Earth System Model as the control climate, we generate two additional members where the NPMM and SPMM are selectively suppressed. We find that both meridional modes energize the tropical variance independently on different timescales. The absence of NPMM leads to a significant reduction of the tropical interannual variability (~35%), while the absence of the SPMM has no appreciable impact on ENSO but significantly reduces the TPDV (~30%). While the relative importance of the NPMM and SPMM may be model dependent, the stochastic atmospheric variability in the extratropics that energizes the meridional modes emerges as a key source of TPDV
Crisi e rimobilitazione: gli italiani, la politica, i partiti nelle indagini campionarie del CISE (2011-2012)
Nella primavera 2012, pochi mesi dopo l\u2019insediamento del governo Monti, i partiti italiani toccavano il punto pi\uf9 basso della loro presa sull\u2019opinione pubblica italiana: altissime percentuali di astenuti e indecisi, con un elettorato demotivato da un\u2019offerta politica ancora incerta (anche a causa della difficile convivenza con un governo tecnico) e quindi incapace di strategie innovative. Tuttavia, \ue8 forse vero che la politica ha orrore del vuoto: l\u2019imminenza delle elezioni amministrative (del maggio 2012) e soprattutto l\u2019ingresso nell\u2019ultimo anno prima delle elezioni politiche segnano una ripresa dell\u2019iniziativa politica, sia da parte dei partiti esistenti che da parte di nuovi attori politici. Il primo a muoversi \ue8 il Movimento 5 Stelle, con un\u2019aggressiva strategia per le elezioni amministrative, in cui registrer\ue0 un grande successo. Ma in secondo luogo \ue8 il centrosinistra a gettarsi in una impegnativa e rischiosa strategia politica basata sulle primarie, che otterr\ue0 tuttavia il grande risultato di una significativa rimobilitazione del proprio elettorato. Tutte queste tendenze sono state puntualmente registrate dalla serie di indagini demoscopiche Osservatorio Politico CISE, condotte ogni sei mesi a partire dalla primavera 2011. I risultati di queste indagini, gi\ue0 pubblicati sul sito web Cise nel corso del 2012, sono raccolti oggi in questo secondo Dossier CISE. Una riflessione sul clima di opinione pubblica che conduce alle elezioni politiche del 2013, che vuole fornire dati utili per interpretare le ultime fasi della campagna elettorale e per inquadrare l\u2019ormai imminente risultato delle elezioni
Risk-adjusted performance indicators in life insurance
The paper approaches the potential of risk-adjusted performance indicators in life insurance, with special reference to a structured policy. The final issue is the computation of risk adjusted indicators as a tool to evaluate the portfolio given a policy structure. The
computation of such indicator could be suitable for the appraisal of both portfolio optimization and potential profits of the structured policy. The selection tool is put into an asset and liability management decision making context, where the relationship between
expected surplus and capital at risk are compared.
The analysis is applied to a structured temporary annuity and is treated by means of Monte
Carlo simulations
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