Quantum anomalies and linear response theory

The analysis of diffusive energy spreading in quantized chaotic driven systems, leads to a universal paradigm for the emergence of a quantum anomaly. In the classical approximation a driven chaotic system exhibits stochastic-like diffusion in energy space with a coefficient $D$ that is proportional to the intensity $\epsilon^2$ of the driving. In the corresponding quantized problem the coherent transitions are characterized by a generalized Wigner time $t_{\epsilon}$, and a self-generated (intrinsic) dephasing process leads to non-linear dependence of $D$ on $\epsilon^2$.Comment: 8 pages, 2 figures, textual improvements (as in published version

Anomalous decay of a prepared state due to non-Ohmic coupling to the continuum

We study the decay of a prepared state $E_0$ into a continuum {E_k} in the case of non-Ohmic models. This means that the coupling is $|V_{k,0}| \propto |E_k-E_0|^{s-1}$ with $s \ne 1$. We find that irrespective of model details there is a universal generalized Wigner time $t_0$ that characterizes the evolution of the survival probability $P_0(t)$. The generic decay behavior which is implied by rate equation phenomenology is a slowing down stretched exponential, reflecting the gradual resolution of the bandprofile. But depending on non-universal features of the model a power-law decay might take over: it is only for an Ohmic coupling to the continuum that we get a robust exponential decay that is insensitive to the nature of the intra-continuum couplings. The analysis highlights the co-existence of perturbative and non-perturbative features in the dynamics. It turns out that there are special circumstances in which $t_0$ is reflected in the spreading process and not only in the survival probability, contrary to the naive linear response theory expectation.Comment: 13 pages, 11 figure

Clinical Outcome of Breast Cancer Occurring after Treatment for Hodgkin's Lymphoma: Case-Control Analysis

Background: To evaluate diagnosis, management and outcome of breast cancer (BC) occurring after irradiation for Hodgkin's lymphoma (HL). Methods: 39 cases of BC in 28 HL survivors were retrospectively reviewed. 21 patients were included in a case-control analysis. Results: The median age at diagnosis of HL and BC was 25.3 and 45.3 years, respectively. The median interval to develop BC was 16.1 years. Eleven women (39.2%) had bilateral disease. Mode of detection of the index breast cancers was by mammographic screening in 17 patients (60.7%), palpable lump in 8 patients (28.6%), clinical examination in two patients (7.1%), and unknown in one patient (3.6%). Case-control analysis showed that histological features and prognosis of BC after HL were similar to those of primary BC, however, for BC after HL, mastectomy was the predominant surgery (P = .001) and adjuvant radiotherapy and anthracycline-based chemotherapy were less frequently used as compared to primary BC (P < .001 and .003, respectively). Conclusion: The previous history of HL does not appear to be a poor prognostic factor for BC occurring thereafter

Clinical outcome of breast cancer occurring after treatment for Hodgkin's lymphoma: case-control analysis

<p>Abstract</p> <p>Background</p> <p>To evaluate diagnosis, management and outcome of breast cancer (BC) occurring after irradiation for Hodgkin's lymphoma (HL).</p> <p>Methods</p> <p>39 cases of BC in 28 HL survivors were retrospectively reviewed. 21 patients were included in a case-control analysis.</p> <p>Results</p> <p>The median age at diagnosis of HL and BC was 25.3 and 45.3 years, respectively. The median interval to develop BC was 16.1 years. Eleven women (39.2%) had bilateral disease. Mode of detection of the index breast cancers was by mammographic screening in 17 patients (60.7%), palpable lump in 8 patients (28.6%), clinical examination in two patients (7.1%), and unknown in one patient (3.6%). Case-control analysis showed that histological features and prognosis of BC after HL were similar to those of primary BC, however, for BC after HL, mastectomy was the predominant surgery (<it>P </it>= .001) and adjuvant radiotherapy and anthracycline-based chemotherapy were less frequently used as compared to primary BC (<it>P </it>< .001 and .003, respectively).</p> <p>Conclusion</p> <p>The previous history of HL does not appear to be a poor prognostic factor for BC occurring thereafter.</p

Physical Electronics

Contains research objectives and reports on two research projects

Physical Electronics

Contains research objectives and reports on four research projects

Quantum decay into a non-flat continuum

We study the decay of a prepared state into non-flat continuum. We find that the survival probability $P(t)$ might exhibit either stretched-exponential or power-law decay, depending on non-universal features of the model. Still there is a universal characteristic time $t_0$ that does not depend on the functional form. It is only for a flat continuum that we get a robust exponential decay that is insensitive to the nature of the intra-continuum couplings. The analysis highlights the co-existence of perturbative and non-perturbative features in the local density of states, and the non-linear dependence of $1/t_0$ on the strength of the coupling.Comment: 10 pages, 4 figure

Factors Influencing Prognosis of Hodgkin’s Disease: Round Table Luncheon

Mesa redonda apresentada no Simpósio Internacional sobre Doença de Hodgkin, realizado no Instituto Nacional de Câncer no Rio de Janeiro — 16 a 20 de Janeiro de 1967. Transcrição da gravação não revista pelos autores