Local Definition and 491 Threads

how can i find the local extrema of x-coordinates in this equation? f(x)=x^4-3x^2+2x

Non-spatial resolution of quanta (split off from "Local realism ruled out?") I have taken the liberty of creating a new thread since this sub-discussion in https://www.physicsforums.com/showthread.php?p=2561841&posted=1" had diverged a bit from the OP. You distinguish two isomorphic...

K, so I don't quite understand how I find a persons weight on a different planet using the said person's weight, the mass of the other planet, and the radius of the planet? So, for example: Max weighs 1000 N on Earth. What would his weight be on a planet with twice the mass of Earth, but...

Thank you for the suggestion. I should say this is the first thread I am starting since I joined physics forums four years ago. So this thread has branched from another one -"Photon entanglement and fair sampling assumption". I noted there that, on the one hand, so far no experiments...

In another thread, we were discussing Zonde's and the De Raedt's model for simulating Bell tests using a purported local realistic computer simulation. I have broken out into this new thread some results which will be interesting to those of you interested in this subject. I will start out by...

It is my understanding that in string theory, loop quantum gravity, the 'asymptotic safety' approach, and in semiclassical quantum gravity, local Poincare symmetry is exact. But there are things like DSR (does the D stand for Deformed, or Doubly? I've heard people say it either way), which...

Homework Statement Given a BVP: \Delta(u)+u=1 in \Omega u=0 on \partial\Omega using linear piecewise functions, calculate the corresponding local stiffness matrix on the reference triangle : {(x,y); 0<=x<=1, 0<=y<=1-x}. The domain is a square with one point in the middle (at...

I just have a small question regarding lorentz cavity: Refer to a small lorentz cavity in a uniformly polarised dielectric. as shown in fig. E_{ex}: External electric field. E_{P}: Electric field in the uniformly polarised dielectric (when sphere has NOT been cut out) E_{L}:Electric field...

Hi, I understand that the local max of a function is the point at which the y value of the function is larger than the neighbouring y values of the function. Say we're considering the local max at a of a function f(x). Does the function have to exist on both sides of a for (a,f(a)) to be a...

Homework Statement Find intervals on which function is (a) increasing (b) decreasing (c) concave up (d) concave down (e) local extreme values (f) inflextion points of: Y=1+x-x2-x4 Homework Equations Y=1+x-x2-x4 The Attempt at a Solution (a) To find where function is increasing...

Is there a space that is path connected but NOT locally path connected? I suspect that there must be some example because the theorem on the classification of covering spaces only applies to spaces that are, amongst other things, path connected and locally path connected.

I'm puzzling over a certain aspect of the interpretation of frame-dragging. Frame-dragging says that the angular momentum of a body makes itself felt in a certain way in the curvature of the spacetime surrounding it. In GR, you typically can't point to a certain spacelike surface with a...

I've just listened to an online lecture where Susskind explained Bell's inequality () Basically he shows that classically A\cap \overline{B}+B\cap \overline{C}\geq A\cap\overline{C} Then he uses spin measurements with 0°, 45°, 90° to the z-axis for A, B, C to measure spins of an electron...

Hi all! This is a generic Mathematica question, which hopefully someone can help me with! :) I have a set of data points. I have an interpolating function from those points. I have a graph of that interpolation function. The graph goes like Sin^2, and has about 10 peaks. I want to have...

Homework Statement http://img682.imageshack.us/img682/1220/86316124.jpg Homework Equations The Attempt at a Solution why am i getting this wrong? i am pretty sure about everything and nothing else seems to fit in there.. maybe the last one? but it says decreasing so it must be...

f(x) = cosx, a = \pi/2 since, L(x)=f'(x)(x-a) -f(a) f'(x) = -sinx = -sin(\pi/2)(x-\pi/2) - f(a) I'm stuck as to where to go next, is this even right?

Homework Statement http://img4.imageshack.us/img4/8899/85779053.jpg Homework Equations The Attempt at a Solution could you please check my answers.. I am pretty sure they are good but i just want to be sure.

Well I've got a temporary full-time job at a local Wendys. Needed the money really badly as I quit my last job and was jobless for a while (my stupidity lol). Anyways back to the job. I've worked at a McDonalds before for 2 years so I was able to get this job relatively quickly... I never had...

Homework Statement Consider a function of one variable, f(x), which is continuous on an interval I. If f has a single critical point, x = a, in I, then if that point is a local maximum (or minimum) it must also be an absolute maximum. Explain why this is.Homework Equations Intermediate Value...

Hello Forum, Using a fixed, Cartesian reference frame (i.e., we, observers, are stationary and located at the origin of the system), the trajectory of a particle would be easily described by the parametric (parameter time or arch length) equations [x(t), y(t), z(t)] or [x(s),y(s),z(s)]...

Many interesting proofs in GR (regarding black holes and singularities, etc.) involve topological methods. However, I don't understand how a theory embodied in Einstein's equations, which appear to me to be local rules of evolution, can ever change the topology since a patch of spacetime...

What is a local invariant? For instance, at http://en.wikipedia.org/wiki/Differential_geometry#Symplectic_geometry it is said that curvature is a local invariant for Riemannian geometry. What is meant by that? What are other examples of local invariants? Thanks!

I would like some tips about what book I should read if I want to properly understand the relation between local symmetry and forces in gauge theories. And with properly uinderstand I mean a combination of mathematics and intuition/visualization. On the topic of QFT I have the books by Zee (...

http://arxiv.org/abs/0908.3408

Homework Statement Show that the function f(x) = \frac{x^8 + 9x^9 - 12x^{13}}{1 + x^3 - x^6} has a local minimum at x = 0. Homework Equations The Attempt at a Solution If f is to have a local minimum at x = 0 then we must have f'(0) = 0. Without typing up the tedious...

Dear PF could you advise me Whether I understand properly or not: In an arbitrary space-time (with an arbitrary curvature) in any sufficiently little region we can go to Local Inertial Frame of Reference - sit into the free falling lift. Being there our experiments are the same as we have...

I have been walking around with the notion that "quantum entanglement implies a sort causal relationship due to the states having a shared history". I am now not so sure that this is correct. When I talk about entanglement, I use the argument that the preparation of the entangled state...

Hi, I would like to know what local density of states (LDOS) is and what differences it has with projected density of states? Also, when we choose a smaller isolevel we have a denser local densities of states, why? Regrds,

In which direction lies the center of the local group?

In Hatcher's book, http://en.wikipedia.org/wiki/Talk:Coherent_topology, see the very end of page 135 and the beginning of page136 for the definition of the local degree of a map S^n-->S^n. I don't get how the local degree degf|x_i could be anything else than ±degf: In the diagram of page 136...

I've just been reading about how complex functions can be defined on the extended complex plane. They start with rational functions as examples, and defining them at oo so they're continuous at oo in a sense. Eg, 1/z would be defined to be 0 at z = oo. I understand that given a holomorphic...

If there is Dark Energy expansion of space throughout this Universe why is it not noticed, at least to some extent, within our Solar system? Can it only be noticed on a Grand Scale?

F(x)=x^m * (1-x)^n where m and n is greater or equal to 2? find the x coordinates of local extrema? would my answer be with respect to m and n? or do i plug in a number for these variables

Can someone please explain to me this internal symmetry... Also please do take mind that i don't have strong mathematical knowledge, YET... but can u state out the conceptual, non-mathematical, principles in local U(1) Guage -Invariance and how it reasons for virtual phton exchange which...

How i can see the right lorentz invariance in lqg?

A while ago I was having an interesting thread here about the possibility of local MWT, MWT as a local explanation of the entanglement experiments. In re-reading this discussion I was wondering whether the proposal of MWT as a local theory means: a) Hidden variables are necessary but MWT...

If f(x,y)= xy+(1/x)+(1/y) I find that fx= y-(1/x2)=0 and fy=x-(1/y2)=0. Solving for coordinates x and y by substituting the equations, I find that y=0 or 1. However, if i try to solve for x-coordinates with y=0, I get an infinity. So does that mean I ignore the possibility of y=0? Another...

[SOLVED] Determining Local Extrema with Lagrange Homework Statement Find local extram of f(x,y,z) = 8x+4y-z with constraint g(x,y,z) = x^2 + y^2 + z^2 = 9 Homework Equations \nabla f(x,y,z) = \lambda g(x,y,z) The Attempt at a Solution So I did the partial derivatives for F and...

please help me out! military service? or ph.d in local univ? hello~ i just started my Masters in Physics. and i have a problem. AS A VICTIM OF Kim Jong-il(i live in S.Korea lol), i got to do my military service. And I can think of only 2 options for now 1. keep studying here and finish my...

I am trying to debug a SUPG FEM code for flow problems (based on Brooks Hughes 1982) and have a question about the Lumped Mass Matrix. My understanding of the Lumped Mass Matrix is that for any given element the mass of that element is simply distributed evenly over the number of nodes. In...

hi, g.r speeks of the ability to constract local lorentz frame. how can an observer construct such a frame if spacetime is curved? what are his rods and clocks? it seems that if one tried to construct a "hive" of coords using a ruler, then it will not cross as expected... he might even...

Is it possible to describe spontaneous breaking of the local gauge symmetry in the standard Hamiltonian formalism, without any manual redefinition of the gauge field( A(r) -> A(r)+▽Λ(r) )? Detailed description of my question is given below.(Quite lengthy.. sorry.) 1. By the 'standard...

If you are under 17 you will not be allowed into the mall after 5 PM on Fri. and Sat. nights unless you are accompanied by an adult. http://cbs3.com/local/Delaware.Mall.Teen.2.769257.html I'm so glad they instituted this rule. The stupid kids that hung out there would just fight all of the...

Why isn't our Local Group's dipole for Microwave Background Radiation pointed towards the center of mass for our Local Supercluster? Clusters are suppose to be just infalling towards gravitational well of it's supercluster. http://en.wikipedia.org/wiki/Cosmic_microwave_background" See...

Why is local gauge invariance needed in qft? I read that is allows interactions whereas global gauge invariance does not but was given no reason.

Homework Statement y1'= −4*y1+y2+y1*y2 y2'= −2*y1−y2+y1*y1 Determine the three critical points of the system and their type of local phase portrait (stable node, unstable, saddle point, spiral, center, no node) Hence I need to get three critical points (x1,y1), (x2,y2) & (x3,y3) and their...

Homework Statement This theorem is from Shiryaev. Can someone PLEASE explain how they are using the little o notation here. It makes no sense to me how they say that a FIXED real number is little o of something. I thought f(n) = o(g(n)) mean that for ever c>0 there exists an n_o such that when...

Can a space be path-connected and not locally path-connected? (To be clear, "locally path-connected" just means that there is a basis of path-connected of sets.) My general intuition says no, but my intuition seems to usually be wrong...and this would explain why Hatcher keeps referring to...

The Phillies game isn't on local TV today, it's only on MLB tv. That's just not right. Americans should not have to live this way.

Homework Statement a) Graph y = -x^5 +5x -6. Include coordinates of local max, min, and points of inflection. Indicate the behavior as x-> -infinity, x -> infinity. b) Find in slope-intercept form the equation of the tangent line to the curve at x = 2. Homework Equations The Attempt at a...