Local Definition and 521 Threads

in zener tunneling phenomena, are the carriers locally generated or non-locally generated? i.e, should we assume the process as though it were generation of holes in the valence band and electrons in the conduction band? i hope someone could shed some physics on this concept. thanks.

1. According to the First Derivative Test for local extrema, if f' doesn't change sign at c, then f has no local extreme value at c. But for a question on my book, f(x)=(4-x^2)^(-1/2), the critical point is 0, but i think it doesn't have local extreme because the derivative doesn't change sign...

http://arxiv.org/abs/0710.3740 Masses for the Local Group and the Milky Way Yang-Shyang Li (1), Simon D. M. White (2) ((1) Kapteyn Astronomical Institute, (2) Max-Plank-Institut für Astrophysik) 10 pages, 5 figures, Submitted to MNRAS (Submitted on 19 Oct 2007) "We use the very large Millennium...

One approach to get a relativistic QM might be to take hamiltonian as sqrt(p2c2 +m2c4). But apparently this does not work because expanding H in inverse powers of c2 will lead to higher order derivative in space. Apparently, one reason this is bad is because higher derivatives mean that the...

I came across this quote recently: "The general theory of relativity teaches that the inertial mass of a given body is greater as there are more ponderable masses in proximity to it; thus it seems very natural to reduce the total inertia of a body to interactions between it and the other...

As far as I can understand space is af manifold with some metric on it. A manifold is described with some charts (coordinates), but how do I relate these coordinates with ex. physical coordinates of some particle. Is it like this: if I'm in some laboratory I make some cartesian coordinate...

Is BM “Bohmian Local” actually Local Is BM “Bohmian Local” actually Local The debate over “local” as defined by Bohmian Mechanics compared to the “local” described by “Einstein Local” and “Bell Local” constantly invades and disrupts the discussions of various threads. This thread is to...

Hi pervect I was going to put this material in the thread where we discussed this topic but I'm unable to locate that thread. Sorry for the unorthodox creation of a new thread for this. I just thought it was important to talk about. :) I've been thinking hard about our discussion about the...

I find the one on wikipedia to be a bit intimidating. It says that... "A topological space is said to be locally path-connected if it has a base of path-connected sets." We have really not covered this notion of "base" in my course, and even though I know what it is, I don't have any...

I have to prove the map g:torus --> (S^2 3 dimensional sphere of radius 1) is a C infinity map in my assignment. The torus is parameterized as x(u,v)=(3+cos u)(cos v) y(u,v)=(3+cos u)(sin v) z(u,v)=sin u The map g is given by g=[6yz/(x^2+y^2+z^2+8), 3-sqrt(x^2+y^2), -xz/sqrt(x^2+y^2)] I...

There is a local physics projects for juniors taking physics. I need some good ideas, can anybody suggest some?

Preamble: I have yet to find a reason to abandon my support of a LOCAL interpretation of QM; especially in relation to EPRB. It is therefore my hope that we might here bring the issue to a head. Given the frequent verbal misunderstandings across the LOCAL--NONLOCAL divide, it is also my hope...

Local maximum point... Homework Statement f(x)=xe TO THE POWER OF -ax x E R a > o Show that f(x) has a local maximum and express this point's coordinates in terms of a.The Attempt at a Solution I think dy/dx = -axe TO THE POWER OF -ax Correct? I don't know where...

I'm interested in studying LOCAL theories within QM. I have the impression that the following theories claim to be such: MWI (Everett) RQM (Rovelli's Relational QM?) QFT (Originated by ?) LQM (There's a book titled ''Local QM'' as I recall.) + Questions: 1. Are there any other LOCAL...

Marco Genovese has put out a review that fairly well summarizes where things are at in tests of Bell's Theorem. He has done similar papers previously, and the references are quite comprehensive (there are 505, and they cover the spectrum). Research on Hidden Variable Theories: a review of...

So I've been working on this problem. I am given the metric in Kruskal coordinates, so ds^2=32M^2exp(-r/2M)/r(-dT^2+dX^2)+r^2(dθ^2+sin^2(θ)dΦ^2) And the path of a particle is X=0 T=λ θ=π/2 Φ=0 And the path of the observer is X=-1/2*T+1/2 θ=π/2 Φ=0 And I am asked to find the 3...

Has anyone heard the word "Tret/treat"? (Not sure how it's supposed to be spelled.) It's used interchangably with treated, and pronounced to rhyme with 'bet'. Its a word I've always been familiar with, but was recently told that once you get more than a few miles outside of Hull no one knows...

How do you name a physical quantity that can be defined at a given point in space: pointlike? local? Say energy density.

We had an initiative that will prevent government seizures of property, via eminent domain, for purposes private development. I really liked seeing that one. A big fat aye for that one! I have a new approach to law and order taxes. I have always supported taxes for law enforcement, but I...

Carl Brannen is having a real triumph in Hawaii He and the famous Japanese physicist Koide are giving talks back to back today and their slides are on line. It seems like on about half his slides (many many anyway) Koide is referring to two equations of Brannen's which Koide has named "the...

Hi, For a first order Diff Equa. x'=f(x,t) and the IC: x(0)=x_0. with t from [0 to infinity) If f(x,t) doesn't satisfy the Lipschitz condition, can I say for sure that there doesn't exist a global unique solution? I think the answer is "no" but I am not sure. Can you all confirm...

I wonder: Would a meeting of dedicated local realists, to discuss QM, fill a phone booth? (We appear to be such a small minority among the great range and depth of PF participants.) However, before gathering in the phone booth, let's each take advantage of the assembled world media and make an...

It gets worse, to be sure it would be best to drive a red, white and black car around here,on a vist to the local garage for fuel in the 5mins i was there 3 vehicles arrived with pigeons encrusted on them, on the drive home it was , dead rabbit, dead rabbit, dead fox, bloody hell a pigeon...

The volume form on a Riemannian manifold is usually defined either in terms of a local holonomic frame or orthonormal frame. Since it's defined globally, I would like there to be a global definition, like there is with symplectic manifolds (vol = ωn). Is there one?

http://img86.imageshack.us/img86/223/subaru048us.jpg http://img93.imageshack.us/img93/286/subaru055aa.jpg http://img93.imageshack.us/img93/2528/subaru063mt.jpg btw, if anyone wants to see the rest: http://forums.montrealracing.com/showthread.php?t=338103&page=3

what is the essentail difference between local density of states and density of state? It is very difficult to figure it out

For f(x,y) = x^2 + y^2 + 3xy I need to find the critical points and prove whether or not they are local minima, maxima or saddle points. I thought the only critical point was (0,0) since Df = (2x + 3y, 2y + 3x) = 0. Doesn't this make (0,0) a local min? The reason I doubt this now is because upon...

Is the speed of light measurement dependent on the tick rate of different clocks? Hello I want to ask the following questions: If Clock A is undergoing only a natural gravitational time dilation, and possesses 0 rate of change in time dilation, and if it is measuring seconds at a different...

Let G \subset \mathbb{R}^{n}\mbox{ open } a \in G f : G \rightarrow \mathbb{R} f \in C^{1}(G) Df(a) = \overrightarrow{0} Then: (i) if D^2f(a) is positively definite, then f has local minimum in a (ii) if D^2f(a) is negatively definite, then f has local maximum in a (iii) if...

Let A be a field of N integers and A[0] = A[N+1] = infinity. Element A[i] is called a local minimum if A[I-1] >= A[i] <= A[I+1]. Find an alogrithm that will find some local minimum in a time asymptotically better then O(n). Hint: Consider that in each field deffined as before there must exist at...

Let A be a field of N integers and A[0] = A[N+1] = infinity. Element A[I] is called a local minimum if A[I-1] >= A[I] <= A[I+1]. Find an alogrithm that will find some local minimum in a time asymptotically better then O(n). Hint: Consider that in each field deffined as before there must exist at...

Mathematical expression of Bell's "local realism" I have started this thread to continue a discussion with NateTG that was starting to get a bit off-topic there. I will repeat the base comment and then reply to NateTG's last comment. I would invite anyone interested to please join in...

I'm having a hard time understanding why the rationals are not locally compact. The definition of local compactness is that every neighborhood of x in X is contained in some compact subset of X. But what are the compact subsets of X? I think this is my biggest problem. I know that the...

I did look through this forum for other threads on this topic, but didn't find any. If this has already been discussed, then please let me know where the thread is. A common model for the expanding universe is an expanding balloon upon which some dots have been drawn. A well know flaw in this...

This post is motivated by some of the discussion on the "Is QM inherently non-local" thread. The goal is to demonstrate that there is a local hidden interpretation possible for any signal local theory. This interpretation will be Bell local, but not Bell realistic. So, let's say we have a set...

Ballot box stuffing between the primaries and the recount: http://www.phoenixnewtimes.com/Issues/2005-10-27/news/dougherty.html

i have this following code with local var as a "ref. to ptr" class node { CType* data; CTYpe* operator*() { return data; } } void F(node *a, node *b) { CType*& tp; tp=**a; } I get the error "Cannot convert CType* to CType*& which i sort of understnad but i do not know how...

Do you know why computer A can ping computer B but computer B can't ping computer A ? Firewalls on or off in this local cable sharing are not a problem. Just now that I can't do things like setting up [\\computerAName\ASharedFolder] from computer B's sharing widzard anymore. How can i fix this...

ok so in the problem f(x)= x + 9/x, I know how to write where f is increasing, but how do you write how it's decreasing? Is it written as [-3,0)U(0,3]? since x=0 is a vertical asymptote wouldn't all the x-values between -3 and 3 be as close to 0 as possible?

we're doing partial derivatives, and i thought i understood them until: f(x,y)=-x^2-y^2-10xy+4y-4x+2 we are meant to find and classify all local extrema. i got: f_x=-2x-10y-4 and f_y=-2y-10x+4 i've never had two variables at this stage, and i can't solve for any of the points. the...

No no, this isn't a long rant on biased media and different portrayals of world events... its about poker. yes, that's right. With two supreme court vacancies, terrorist attacks in London, record low unemployment rates... what is taking up half of the front page news in my city? Texas Hold Em...

Hello, in my lecture notes I have made a note that if V is a local potential, then <r|V|r'> is diagonal. Is this true, and how come? It popped up with the Lippmann-Schwinger equation, and I know it's important that V is local, but does really locality implicate diagonality? Jonas

In all the websites that offer a "local" service to find businesses near you I think that Google has the best. They have this satellite option that allows you to see clear images of buildings. I am sure you can spot your house with this thing once you zoom right it. Though this is not...

I know that, given an arbitrary unitary matrix A, it can be written as the product of several "local" unitary matrices Ai -- local in the sense that they only act on a small constant number of vector components, in fact it is sufficient to take 2 as that constant, which is best possible. For...

This thread asks: Can we be sure no local black hole exists? It will, I hope, focus on an effort to make at least an OOM estimate of photographic detection (visible light) by “weak quasar” radiations that may be produced as solar wind (or ISM if the BH is far away, where the solar wind density...

http://www.foxnews.com/story/0,2933,153135,00.html http://www.msnbc.msn.com/id/7477836/

the question is http://home.earthlink.net/~urban-xrisis/clip_image002.jpg what is the difference between a local max/min and a relative max/min? is the correct answer b?

For each patch, a coordinate function maps the local coordinates to the euclidean space. Collection of all patches with coordinate functions covers the whole manifold. What is a transition function and what is a change of coordinates? Is it that you got one set of local coordinates throughout...

hey guys...Can someone help me out here...i'm trying to understand what the difference between a global maximum and a local maximum is? arn't they the same??

the question is http://home.earthlink.net/~urban-xrisis/clip001.jpg I got a different answer than what the book says... so I need to find the formula of the graph. H'(3)=f(3)=2 m=\frac{\Delta y}{\Delta x} 2=\frac{\Delta y}{x- \int^3_0 f(t)dt} y=2(x+2) y=2x+4 the book's answer...