The Data Breach Dilemma: Proactive Solutions for Protecting Consumers’ Personal Information

Data breaches are an increasingly common part of consumers’ lives. No institution is immune to the possibility of an attack. Each breach inevitably risks the release of consumers’ personally identifiable information and the strong possibility of identity theft. Unfortunately, current solutions for handling these incidents are woefully inadequate. Private litigation like consumer class actions and shareholder lawsuits each face substantive legal and procedural barriers. States have their own data security and breach notification laws, but there is currently no unifying piece of legislation or strong enforcement mechanism. This Note argues that proactive solutions are required. First, a national data security law—setting minimum data security standards, regulating the use and storage of personal information, and expanding the enforcement role of the Federal Trade Commission—is imperative to protect consumers’ data. Second, a proactive solution requires reconsidering how to minimize the problem by going to its source: the collection of personally identifiable information in the first place. This Note suggests regulating companies’ collection of Social Security numbers, and, eventually, using a system based on distributed ledger technology to replace the ubiquity of Social Security numbers

Negative Elliptic Flow of J/ψJ/\psi's: A Qualitative Signature for Charm Collectivity at RHIC

We discuss one of the most prominent features of the very recent preliminary elliptic flow data of $J/\Psi$ meson from the PHENIX collaboration \cite{Silvestre:2008tw}. Even within the the rather large error bars of the measured data a negative elliptic flow parameter ($v_2$) for $J/\Psi$ in the range of p_T=0.5-2.5 \GeV/c is visible. We argue that this negative elliptic flow at intermediate $p_T$ is a clear and qualitative signature for the collectivity of charm quarks produced in nucleus-nucleus reactions at RHIC. Within a parton recombination approach we show that a negative elliptic flow puts a lower limit on the collective transverse velocity of heavy quarks. The numerical value of the transverse flow velocity $\beta_T$ for charm quarks that is necessary to reproduce the data is $\beta_T(charm)\sim 0.55-0.6c$ and therefore compatible with the flow of light quarks.Comment: 4 pages, 3 figures; to be published in EPJ A; Changes: Added B-meson elliptic flow and data on non-photonic electron v_2 to Fig. 2; Added a plot showing the quark v_2; Added discussion about D^0 flo

Spillover Effects of Maternal Education on Child's Health and Schooling

This is the first study investigating the causal effect of maternal education on child's health and schooling outcomes in Germany. We apply an instrumental variables approach that has not yet been used in the intergenerational context. For that purpose, we draw on a rich German panel data set (SOEP) containing information about three generations. This allows instrumenting maternal education by the number of her siblings while conditioning on a set of variables describing the grandparents' social status and the area where the mother grew up. Given these variables, the number of siblings generates exogenous variation in the years of education by affecting the household resources available per child. We present evidence for strong and significant effects on schooling outcomes for both sexes. And, we find substantial effects on health behaviour for adolescent daughters, but not for adolescent sons. We show that possible concerns for the validity of the instrument are unlikely to compromise these results. We also discuss assortative mating and household income as possible channels of causality.Intergenerational mobility, returns to education, health, instrumental variables

Integrability and weak diffraction in a two-particle Bose-Hubbard model

A recently introduced one-dimensional two-particle Bose-Hubbard model with a single impurity is studied on finite lattices. The model possesses a discrete reflection symmetry and we demonstrate that all eigenstates odd under this symmetry can be obtained with a generalized Bethe ansatz if periodic boundary conditions are imposed. Furthermore, we provide numerical evidence that this holds true for open boundary conditions as well. The model exhibits backscattering at the impurity site -- which usually destroys integrability -- yet there exists an integrable subspace. We investigate the non-integrable even sector numerically and find a class of states which have almost the Bethe ansatz form. These weakly diffractive states correspond to a weak violation of the non-local Yang-Baxter relation which is satisfied in the odd sector. We bring up a method based on the Prony algorithm to check whether a numerically obtained wave function is in the Bethe form or not, and if so, to extract parameters from it. This technique is applicable to a wide variety of other lattice models.Comment: 13.5 pages, 11 figure

Interlacing Families II: Mixed Characteristic Polynomials and the Kadison-Singer Problem

We use the method of interlacing families of polynomials introduced to prove two theorems known to imply a positive solution to the Kadison--Singer problem. The first is Weaver's conjecture $KS_{2}$ \cite{weaver}, which is known to imply Kadison--Singer via a projection paving conjecture of Akemann and Anderson. The second is a formulation due to Casazza, et al., of Anderson's original paving conjecture(s), for which we are able to compute explicit paving bounds. The proof involves an analysis of the largest roots of a family of polynomials that we call the "mixed characteristic polynomials" of a collection of matrices.Comment: This is the version that has been submitte

Bound states in the one-dimensional two-particle Hubbard model with an impurity

We investigate bound states in the one-dimensional two-particle Bose-Hubbard model with an attractive ($V> 0$) impurity potential. This is a one-dimensional, discrete analogy of the hydrogen negative ion H$^-$ problem. There are several different types of bound states in this system, each of which appears in a specific region. For given $V$, there exists a (positive) critical value $U_{c1}$ of $U$, below which the ground state is a bound state. Interestingly, close to the critical value ($U\lesssim U_{c1}$), the ground state can be described by the Chandrasekhar-type variational wave function, which was initially proposed for H$^-$. For $U>U_{c1}$, the ground state is no longer a bound state. However, there exists a second (larger) critical value $U_{c2}$ of $U$, above which a molecule-type bound state is established and stabilized by the repulsion. We have also tried to solve for the eigenstates of the model using the Bethe ansatz. The model possesses a global \Zz_2-symmetry (parity) which allows classification of all eigenstates into even and odd ones. It is found that all states with odd-parity have the Bethe form, but none of the states in the even-parity sector. This allows us to identify analytically two odd-parity bound states, which appear in the parameter regions $-2V<U<-V$ and $-V<U<0$, respectively. Remarkably, the latter one can be \textit{embedded} in the continuum spectrum with appropriate parameters. Moreover, in part of these regions, there exists an even-parity bound state accompanying the corresponding odd-parity bound state with almost the same energy.Comment: 18 pages, 18 figure