Properties Definition and 1000 Threads

I've just started a masters in physics after a 4-year break and am having some real trouble getting back into the swing of things! We have been asked to prove some properties of gamma matrices, namely: 1. \gamma^{\mu+}=\gamma^{0}\gamma^{\mu}\gamma^{0} 2. that the matrices have eigenvalues...

how would I show that y'(t) = x(t) * h'(t) and y'(t) = x'(t) * h(t) I know that in an LTI system y(t) = x(t) * h(t) = \int x(\tau) * h(t-\tau) from \infty to -\infty But how would I go about trying to prove the first two equations?

Homework Statement I'm just not sure what the answer to this is. I think it's an identity for e^x and ln, but I've never had a course that dealt with e^x or logs. So I don't know. What is the answer to e^14ln(x)? It's part of a larger problem, but I can't get the rest of it done until I...

Dear all I have pooled the following facts or misnomers that I have heard or been told over the years about glass. Please comment on whether they are indeed correct and factual depictions of what is happening.1) You can see through glass because it does not absorb visible radiation (or absorbs...

Homework Statement Write down an equation to describre a wave \psi(x,t) with all of the following properties a) It is traveling in the negative x direction b) It has a phase velocity of 2000ms-1 c) It has a frequency of 100kHz d)It has an amplitude of 3 units e) \psi(0,0)= 2 units...

Hi, i would just like to clarify some terms used in aerodynamics with you guys here and find out more about these terms at the same time. Turbulent shear layer: Does this term refer to the first layer of air immediately adjacent to the wall surface over which the air flows? Turbulent...

I am studying the very first chapter of analysis, but can't quite get through this problem: Prove f −1(f(A)) ⊇ A Prove f(f −1(B)) ⊆ B

Dear all, is the relation between chemical composition of a material and its physical properties a peering relation or a relation of subordination？

Homework Statement Given a Hermitian operator A = \sum \left|a\right\rangle a \left\langle a\right| and B any operator (in general, not Hermitian) such that \left[A,B\right] = \lambdaB show that B\left|a\right\rangle = const. \left|a\right\rangle Homework Equations Basically those...

Hi, I'm finished studying ondulatory and I have maany questions I still don't understand. I would be thankful if someone could help me in that, Because I'm pretty lost. I'm going to ask them in letters (A, B, C...), each one is a different doubt.A man has photographed (with a fixed...

1) I can assume all these matrices to be 2x2. We have matrix A and B and AB = BA, that is, they commute.. Prove if C = A^2 + 2*A and D = A^3 + 5 * I (I is identity matrix), then CD = DC. Then give a theory that generalizes this. 2) why does R(theta)R(phi)=R(theta+phi)? (explain with...

Does anybody know about a comprehensive list of cosmological models and their properties? E.g. FRW, dS, AdS, ... Goedelspacetime, ... with metrics g, Christoffel symbols, Riemann tensors, Ricci, Ricci scalar, Kretschmann scalar, ... Tom

I have looked everywhere to find a simple, easy test to find whether a wave is longitudinal or transverse, I've read my textbook and I think it may be to do with polarisation but I am not quite sure how, or someone said that passing the wave through a vacuum would determine the type of wave. any...

Suppose that limx->c f(x) = infinity and limx->c g(x)=l where l is a real number. Prove the following. limx->c[f(x)+g(x)]= infinity limx->c[f(x)g(x)]= infinity if l > 0 limx->c[f(x)g(x)]= -infinity if l < 0 I have the proof for these already, but I couldn't understand them, would someone please...

Homework Statement \sqrt{\sum}x^{2}_{i}\leq\sum|x_{i}|\leq\sqrt{n}\sqrt{\sum}x^{2}_{i} *The sums are all from i=1 to n.* Homework Equations The Attempt at a Solution I'm very new to proof-based math, and just looking for some help to get started with this one. Thanks in advance.

Hello I am having a problem with the following question. Homework Statement Determine which statements are true in 3. (Select all that apply.) (a) Two lines parallel to a third line are parallel. (b) Two lines perpendicular to a third line are parallel. (c) Two planes parallel to a...

Hello all! :smile: I am (painfully) going through the first chapter of Spivak's Calculus. At one point he introduces the property: if a, b, and c are any numbers, then a\cdot(b+c) = a\cdot b +a\cdot c. He then uses this property in an example in which he shows that the only time that a - b =...

Hi, I was wondering if I correctly applied the properties of the supremum of a set to solve the following proof. I feel like I "cheated" in the sense that I said, "Let s = Sup(B) - epsilon. Homework Statement If \sup A < \sup B, then show that there exists an element b \in B that is an upper...

PBS will split unpolarized light into beams of differing polarization, but what will it do to linearly polarized light?

Homework Statement ∫(from pi/4 to pi/2)sin x/x ≤ 1/√2. Homework Equations The Attempt at a Solution I know the pi/4≤x≤pi/2 and so 1/√2 ≤ sin x ≤ 1 and i have tried to manipulate this to no end and it has annoyed the living daylights out of me

I'm mainly looking for how "real" life properties are explained. I'm looking for a book on the properties of matter. Something that covers the why liquids flow, the detailed properties of water, how different colors come about, etc, properties of solids, etc. Why are soft things soft? Stuff...

Hi, I need a hand with my reasoning on the following question. I have answered all the questions, but not too sure weather they are correct. Please guide me or point me on the right direction if they are not correct. Regards 1. A system defined by the following equation y(t)=[x(t-2)]^2...

For reference, let \mathbb N^{\infty} denote the set of all \infty-tuples of the form (n_{1}, n_{2}, \dots) with n_{i}\in \mathbb N ,\,\forall i, and let \mathbb N^{*}=\{1,2,3,\dots\}. Let n\in\mathbb N^{*}. Then by the Fundamental Theorem of Arithmetic, we can represent n as a unique...

Let's say we have the statement \sum^{\infty}_{0}f(x)=\frac{\sum^{\infty}_{0}g(x)}{\sum^{\infty}_{0}h(x)} does this imply that \int^{\infty}_{0}f(x)=\frac{\int^{\infty}_{0}g(x)}{\int^{\infty}_{0}h(x)}? Also if \sum^{\infty}_{0}f(x)=\sum^{\infty}_{0}g(x) does this imply that f(x)=g(x), or...

Consider an ARCH(1) model: Xt = σtZt, where Zt~ i.i.d. N(0,1) σt2 = w0 + w1 Xt-12 Find (i) E(Xt) and (ii) the autocovariance function γX(h) for h=0,1,2,3,..., assuming the process is second-order stationary. Solution: (i) E(Xt) = E[E(Xt|σt2)] =E[E(σtZt|σt2)] =E[σtE(Zt|σt2)] =...

Greeting Physics Forums; my first post here. Thanks in advance for your time! Approximately how many soundwaves compose what we can say is a single noise, like a drumbeat? I know there are multiple frequencies involved and our brain interprets this in it's own way. There is interference...

Do gravitational forces discriminate against chemical energy potential? Could the gravitational forces of three substances, equal in density, but differing in chemical properties affect each other differently based on their differences in chemical energy potential? Take two separate bodies of...

hello, I'am stuying the laplace transform and have problems with understanding the follow thing my course says: lim s->+inf F(s)=lim t->0 f(t) lim s->0 F(s)=lim t->+inf. f(t) I would like to understand it because I have the feeling that this are important properties. Thank you very...

Homework Statement I'm self-studying Abstract Algebra from baby Herstein. This is an exercise in its problem sets: Suppose that G is closed under an associative operation such that 1. given a,y in G, there is an x in G such that ax = y, and 2. given a,w in G, there is a u in G such that ua =...

Homework Statement Suppose we are given the following information about a continuous-time periodic signal with period 3 and Fourier coefficients a_{k} 1. a_{k} = a_{k+2} 2. a_{k} = a_{-k} 3. \int_{-0.5}^{0.5}x(t)dt = 1 4. \int_{0.5}^{1.5}x(t)dt = 2 Determine x(t) Homework Equations if x(t)...

¿ Can diff. EM frequencies create diff. magnetic fields with diff. properties ? I understand that a magnetic field is generated via moving charged particles . Electricity and magnetism are linked through electromagnetism . Electromagnetism can be in different wavelengths and frequencies but...

Homework Statement List the 4 properties and characteristics of electric field lines. Homework Equations I was not able to get them all and the ones that I did get I am confused that if it is really a characteristic or a property The Attempt at a Solution 1. Characteristic...

The Supergolden ratio is the solution of x3=x2+1. \psi = \left({{\sqrt{31}}\over{2\ \times 3^{{{3}\over{2}}}}} {{29}\over{54}} \right)^{{{1}\over{3}}} {{1}\over{9\,\left({{\sqrt{31}}\over{2\ \times3^{ {{3}\over{2}}}}} {{29}\over{54}}\right)^{{{1}\over{3}}}}} {{1}\over{ 3}}\approx...

Is it true that every material can be attracted by a magnetic field provided that the magnetic field is STRONG enough?

I am an ameteur physicist (i actually have my degree in meteorology), and i have some questions about the EM properties of liquid metals or ferrous liquids when in spherical form. I understand if you are too busy or if i sound off, but if you do have the time to answer a few questions, it would...

A physics hobbyist such as myself, trying to understand high-energy experiments from the recent decades, often hears about symmetries in the model, conservation laws, Feynman diagrams and so on. These are all intuitive properties but very far from a basic world view of "what happens...

Dear All, I am curious to know about some materials listed below- Mumetals, Permalloy, Supermalloy, Permendur, Perminvar and Sendust. I am interested to study there magnetic properties like permeability, hysteresis, temp. dependence of magnetism etc, if possible coefficient of...

Homework Statement Determine which, if any, of the following functions have the properties of auto-correlation functions. Justify your determination. http://rndpakistan.com/projects/hswhs/images/ques.jpg Homework Equations [PLAIN][PLAIN]http://rndpakistan.com/projects/hswhs/images/autop.jpg...

Hello guys I've asked to prove following equation on determinants, here it is; Using the properties of determinants & without expanding prove that, see attachment, I need to verify my answer can some one tell me whether is this correct or not?:smile:

Homework Statement my textbook mentions the following as properties of lines of forces among other things They do not pass through a conductor. They contract longitudinally. They exert a lateral pressure on each other. I want clarification on these points i) Why lines of force do...

Hi, Can anyone tell me at what temperature a 25micron sulphuric acid anodic coating will start to breakdown. I have noticed that after exposure to 135°C the electrical properties of the coating have dropped drastically. Regards Dan

Homework Statement Determine if the system y(t) = sin(x(t)) is time invariant, linear, causal, and/or memoryless. Homework Equations None. The Attempt at a Solution The system is time invariant and is non-linear, but I don't understand why it is causal and has memory.

Does anyone know if steel is still magnetic at over it's melting temp? If it does lose it's magnetic properties as a liquid, at what point does it happen? Gradual or at a certain temp?

Hello, I am nearing the end of my first year. I will have 1-2 months of vacation. I am really interested in getting grasp at least a little around magnetic phenomena. If somebody could recommend me a book where this issue is addressed hard. Where magnetism is explained, but not on the...

If the speed of light were (slightly) different, how would that affect the chemical properties of atoms, if so?

Hi, All: Could someone please tell me or give me a ref. on the basic properties of Gl(n,R) ; R a ring; possibly a division ring, and Gl(n,R) the group (under composition) of matrices invertible over R ? (I imagine we need a ring R with 1 , to talk about invertibility). I...

Which properties of the photon/quantum are random? Spin - Yes Position (within the "range/orbital") - Yes Momentum - Yes Phase - No Polarization - No Coherence (derivative of phase) - No Is the above correct? Please add the properties I missed

In supersymmetry, particles are said to have symmetric partners or something(dont remember what it was called) and those partners where exactly the same but they spun slower, so they had different properties, so why does different spin give different properties of particles?

Please help me prove that the following properties are equivalent Nested Interval Property Bolzano-Wierstrass theorem Monotonic sequence property LUB property Heine-Borel theorem archimedean property and cauchy sequence line connectedness...

1. What properties (that we are aware of/discovered) can be entangled? - spin, polarization etc 2. Can we entangled/disentangled additional properties (between a two photon pair) at any particular time? for example can we have both spin and polarization entangled at same time? - can we...