Dynamical imaginary-time correlations from auxiliary fields quantum Monte Carlo

Quantum Monte Carlo (QMC) simulations of many body fermionic systems are considerably complicated by the well known sign problem. Although very accurate approximation schemes have been developed for the calculation of static properties, like structure functions and energy, the possibility of extending such methodologies to the investigation of dynamical properties is still largely unexplored. Recently, a number of innovative QMC methods have been conceived which map the imaginary time evolution into a random walk in the abstract manifold of Slater determinants. In such approaches the sign problem is not circumvented and still requires approximations, but emerges in a different - and hopefully easier to handle - way. We have focused on the phaseless auxiliary Fields QMC method (AFQMC), developed by Shiwei Zhang. Generalizing the formal manipulations suggested by Assaad et al., we propose a practical scheme to evaluate dynamic correlation functions in imaginary time, giving access to the study of excitations and response functions of interacting fermionic systems. We have explored systematically the effects of the phaseless approximation, underlying the AFQMC technique and its dynamical generalization, via the study of exactly solvable simple models, comparing AFQMC predictions with exact solutions. We will present also results about a two-dimensional electron liquid, providing comparisons with other QMC techniques

Pros-IT CNR : an Italian prostate cancer monitoring project

Aims: The Pros-IT CNR project aims to monitor a sample of Italian males 6518 years of age who have been diagnosed in the participating centers with incident prostate cancer, by analyzing their clinical features, treatment protocols and outcome results in relation to quality of life. Methods: Pros-IT CNR is an observational, prospective, multicenter study. The National Research Council (CNR), Neuroscience Institute, Aging Branch (Padua) is the promoting center. Ninety-seven Italian centers located throughout Italy were involved. The field study began in September 1, 2014. Subjects eligible were diagnosed with biopsy-verified prostate cancer, na\uefve. A sample size of 1500 patients was contemplated. A baseline assessment including anamnestic data, clinical history, risk factors, the initial diagnosis, cancer staging information and quality of life (Italian UCLA Prostate Cancer Index; SF-12 Scale) was completed. Six months after the initial diagnosis, a second assessment evaluating the patient\u2019s health status, the treatment carried out, and the quality of life will be made. A third assessment, evaluating the treatment follow-up and the quality of life, will be made 12 months after the initial diagnosis. The 4th, 5th, 6th and 7th assessments, similar to the third, will be completed 24, 36, 48 and 60 months after the initial diagnosis, respectively, and will include also a Food Frequency Questionnaire and the Physical Activity Scale for the Elderly. Discussion: The study will provide information on patients\u2019 quality of life and its variations over time in relation to the treatments received for the prostate cancer