Problem of attaining constant impurity concentration over ingot height

Equilibrium concentration of impurity-vacancy complexes

On the over-concentration problem of strong lensing clusters

Λ cold dark matter paradigm predicts that galaxy clusters follow a universal mass density profile and fit a well-defined mass-concentration relation, with lensing clusters being preferentially triaxial haloes elongated along the line of sight. Oddly, recent strong and weak lensing analyses of clusters with a large Einstein radius suggested those haloes to be highly overconcentrated. Here, we in...

Coulomb impurity problem in graphene.

We address the problem of an unscreened Coulomb charge in graphene and calculate the local density of states and displaced charge as a function of energy and distance from the impurity. This is done nonperturbatively in two different ways: (1) solving the problem exactly by studying numerically the tight-binding model on the lattice and (2) using the continuum description in terms of the 2D Dir...

the problem of divine hiddenness

این رساله به مساله احتجاب الهی و مشکلات برهان مبتنی بر این مساله میپردازد. مساله احتجاب الهی مساله ای به قدمت ادیان است که به طور خاصی در مورد ادیان ابراهیمی اهمیت پیدا میکند. در ادیان ابراهیمی با توجه به تعالی خداوند و در عین حال خالقیت و حضور او و سخن گفتن و ارتباط شهودی او با بعضی از انسانهای ساکن زمین مساله ای پدید میاید با پرسشهایی از قبیل اینکه چرا ارتباط مستقیم ویا حداقل ارتباط وافی به ب...

Removing Nondeterminism in Constant Height Pushdown Automata

We study the descriptional cost of removing nondeterminism in constant height pushdown automata — i.e., pushdown automata with a built-in constant limit on the height of the pushdown. We show a double-exponential size increase when converting a constant height nondeterministic pushdown automaton into an equivalent deterministic device. Moreover, we prove that such a double-exponential blow-up c...