Computation Definition and 231 Threads

Note: I'm posting this in the Quantum Physics forum since it doesn't really apply to HEP or particle physics (just scalar QFT). Hopefully this is the right forum. In Peskin and Schroeder, one reaches the following equation for the spacetime Klein-Gordon field: $$\phi(x,t)=\int...

Homework Statement Hello! Revising geometric series, I have understood that I have the following issue - I have read again about these series and, please, take a look at what I have gotten as a result (picture attached). If I calculate a future cash flow, that is I take, for example, a = 0,5...

Can anyone help me understand how superposition leads to increased computational ability? I'm pretty sure I have all the background in conventional computing covered, I started programming basic 30 years ago and jumped directly into assembly language (position independent machine-code, then...

This question occurred to me some time ago when I was thinking about whether or not `if` statements are fundamental in computation. Consider a program that manages a single bank account (for the sake of simplicity). The bank account could be defined as something like Account { int...

I'm currently in my final year of BSc(Hons) in mathematics and computer science & A.I (applied math stream). Indeed, I'm starting to think about what masters I want to pursue and the kind of subject I would like to specialize in. I am really interested in quantum computation and the prospects of...

Homework Statement Hello! I would be grateful for the help. Please, take a look at the picture attached. In the sixth column you can see that 50 000 were repaid during this period. My questions are: 1) why in the formula for % this 50 000 were added but not subtracted (the formula is also on...

Hi everyone I am working on entanglement between an atomic system and its spontaneous emission but I don't know how to connect this kind of entanglement with quantum computation, I have read in different articles that entanglement is somehow essential in applications like quantum communication...

let C be the curve of intersection of the parabolic cylinder $x^2=2y$ and the surface $3z=xy$. find the exact length of C from the origin to the point (6,18,36). please help! this is the last question i have left from this assignment and i have no idea how to do it. i have grading to do and a...

Don't know where else in Phyiscs Forums or on the internet in general to ask this, and if it's inappropriate here, I apologize. My question is: is there an open source library or resource that I can access from a C++ program to perform symbolic computation on the level of something like Maple...

I am reading Dummit and Foote, Chapter 13 - Field Theory. I am currently studying Example 4 [pages 515 - 516] I need some help with what D&F call a simple computation. Example 4 on pages 515-516 reads as follows: Now in the above example, D&F write the following: " ... ... In this case, a...

Hi, When we want to solve the Navier-Stokes equations coupled with the conservation of mass for incompressible fluids using the primitive-variable approach, we have to face to the problem that the equation for the continuity equation does not contain the pressure which leads to spurious...

I have a Gaussian distribution about t, say, N(t; μ, σ), and a a Dirac Delta Function δ(t). Then how can I compute: N(t; μ, σ) * δ(t > 0) Any clues? Or recommender some materials for me to read? Thanks!

Define: \[ f(t) := \frac{7^t}{7^t + \sqrt{7}}. \] Without the aid of a computer or calculator, evaluate: \[ \sum_{k=1}^{2013} f \left( \frac{k}{2014} \right). \] (Please show the work.)

Here is the question: I have posted a link there to this thread so the OP can see my work.

Can anybody please help me understand the computation of the integral in the attached image. I shall be grateful.

Homework Statement Compute the 2nd and 3rd Virial coefficients at 300K of Ar. Experimental parameters are mentioned in xlist and ylist below :) Homework Equations My professor has given a hit, which is as follows: "Use the data to determine the (z) compressability (sp?) and plot Z as a...

I have been considering the idea for awhile that all mathematics could be broken down into atomic pieces that are indivisible, and therefore any formula could be determined through a process of elimination by trying every possible mathematical formula. Here is what I have come up with so...

Hi All, I am having some troble with the following integral $$\int_{-c}^{c} \frac{x^3}{(x^2+(y-s)^2)^2}\mathrm{d}s$$ Many thanks as usual

Next semester I am going to write a undergrad thesis about quantum computation, but my background is not from physics but from mathematics and computer engineering. In this talk http://www.youtube.com/watch?v=Rvn_3cCrl9c Andris Ambainis talks about how he got into the field of quantum computing...

Hello all, I've got a somewhat mixed concept question from a Chemical Engineering computational methods class. I'm completely lost with this question, as I do not fully understand what it entails. The question (and data) is this: Homework Statement Data Set Given X Y 0.00 -2.17...

Hi everyone, Can anyone point me into the right direction on how to compute the deceleration parameter (##q_0##) for a radiation dominated universe? I know that q0 is given by ##q_0=-\frac{\ddot{a}(t_0)}{a(t_0) H^2 (t_0)} = - \frac{\ddot{a}(t_0) a(t_0)}{\dot{a}^2(t_0)}=\frac{\Omega_0}{2}##...

Homework Statement q1]] Which of the following pairs of quantum gates commute? Select all that apply. (Gates A and B commute if and only if for any input applying A and then B gives the same results as applying B and then A. This is the same as saying that the unitary transformations commute.)...

This is likely going to be a stupid question given that I am not in com sci, have very little com sci knowledge with regards to information storage/algorithms. I was wondering, if this question has any meaning, what are the costs of scanning for something vs carrying out some integer...

Here is the question: I have posted a link there to this topic so the OP can see my work.

Here is the question: I have posted a link there to this topic so the OP can see my work.

Homework Statement Dear all, I have to find a fast way to compute changes in the level lines as the result of sudden changes in the local gravitational fields (2D space). (Caused by the destruction of a planet for example). I could recalculate everything but it takes too much time for the...

I am looking for a software that can compute the following integral ∫_0^1f(x)\phi(2^jx-k)dx. \phi(x) is scaling function of a wavelet family (especially Daubechies), j and k are scaling and translation parameters respectively.

Here is the question: Here is a link to the question: Calculus help upper and lower half? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Computation of infinite accuracy could be achieved utilizing a box of magnetic pads, filled with magnetic fluid. The pads would fluctuate their fields, thus circulating the fluid. Behind the pads would be a second pad layer; a grid of electric transmitters, connected to a computer running a...

Hi, I just tried to solve the following integral: \int_{-\infty}^{\infty} \frac{2}{1+(2\pi t)^2} \mathrm{sinc}(2t) dt My approach is: Convert both to Fourier domain and the multiplication becomes a convolution. Because of Parsevals theorem, I can either integrate in time or frequency...

Hello! I am living in Germany. Let's say that I want to know the local time in New York, and let's arrange that the local time in Germany is 11:00 o'clock (24-hour clock). Germany's time is shifted 1 hour ahead (UTC +1), and New York's time is shifted 5 hours behind (UTC -5). So the...

Hi all! I must compute a derivative with respect to the components of a unit vector \hat{p}^{i}. In spherical coordinates, \hat{p}^{1}=\hat{p}^{1}(\theta,\phi)=\cos\theta \sin\phi I want to express the derivative \frac{\partial}{\partial\hat{p}^1} as a combination of...

Homework Statement Consider the following integral: I=\int^{\pi/4}_{0}cos(xt^{2})tan^{2}(t)dt I'm trying to compute as many terms as possible of its asymptotic expansion as x\rightarrow\infty. Homework Equations x The Attempt at a Solution Let u=cos(xt^{2}). And...

Hi all, While solving problems related to probability I got stucked with this problem: In some election 4 candidates A,B,C,D has the probability of being elected is 0.4,0.3,0.2,0.1 respectively.If the candidate C discard his candidateship just prior to the election ,then what will be the...

Homework Statement Let a one-qubit system be in the state [SIZE="3"]\left|ψ\right\rangle = \frac{\sqrt{15}\left|0\right\rangle + i\left|1\right\rangle}{4}. If we perform a measurement to see whether the qubit is in the state [SIZE="3"]\left|x_{+}\right\rangle = \frac{\left|0\right\rangle +...

Please help with this: Suppose in recent years, it has only rained an average of 5 days a year. The weather forecast, which has an accuracy of 90%, predicts rain for tomorrow. What is the probability of rain tomorrow? A: <1% B: between 5 and 15% C: between 15 and 80% D: between 80 and...

Homework Statement Find the value of the line integral \int C(e-x^3 - 3y)dx + (tan y + y4 + x) dy where C is the counterclockwise-oriented circle of radius 4 centered at (0,2). The Attempt at a Solution First off, I didn't think this was path independent since the derivative of the dx term...

What is Quantum computation? And what is the scope in this field at present and in near future?

I have a quick question. The problem reads: Prove that there is no integer m such that 3x2+4x + m is a factor of 6x4+50 in Z[x]. Now, Z[x] is not a field. So, the division algorithm for polynomials does not guarantee us a quotient and remainder. When I tried dividing 6x4+50 by 3x2+4x +...

Since I know that this will get lost in the Liar's paradox thread I wanted to separate it out from the thread: In post 18 of the liar's paradox thread Hurkyl writes:" and in post #47 he writes: I would like to know where he is going with this line of thought. A related concept I've seen...

Hi all! this is my first hour on Physics forums! so my question is, which of the 3 named fields (cs, ee, phys) are more active in quantum computation/information? I am a double majored ee/phys and I've passed some cs courses. as far as I see, any quantum lab will contain researches from all...

I am reading chapter three of Huang's Statistical Mechanics and I have a problem with equation (3.22). Having discussed the derivation of the classical cross section for a scattering process, Huang moves on to the quantum version of it. He states that in quantum mechanics the fundamental...

hi simple computation A = 60x60x100 B = 60x60x30 I want to find A*B, by this I mean, I want a 100x30 output matrix where element (k,m) represents the sum of A(i,j,k)*B(i,j,m) over all i,j My brain is simply not working and I'm confusing myself, does anyone have a short line of code to...

As an exercise, I'm trying to compute the class number of K = \mathbb{Q}(\sqrt{30}). By the Minkowski bound, I just need to consider the prime ideals which divide 2,3,5. I've found that (2) = \mathfrak{p}^2_2 (3) = \mathfrak{p}^2_3 (5) = \mathfrak{p}^2_5 where...

Hi, I wrote a piece of MATLAB code to compute a double integral of the form: \int_{a}^{b}\int_{c}^{d}f(x,y)dxdy I went about it using the trapezium rule, so what I did was apply the rule to the x variable first to obtain: \int_{a}^{b}\int_{c}^{d}f(x,y)dxdy\approx\frac{\delta...

Let $f(x)=-x$ for $-l\le x\le l$ and $f(l)=l.$ a) Study the pointwise convergence of the Fourier series for $f.$ b) Compute the series $\displaystyle\sum_{n=0}^\infty \frac{(-1)^n}{(2n+1)}.$ c) Does the Fourier series of $f$ converge uniformly on $\mathbb R$ ? ------------- First I need to...

Homework Statement The problem is in the provided link (it is questions 2.2) http://www.docstoc.com/docs/3817109/Chapter-Problems-A-car-travels-up-a-hill-at-a Homework Equations The Attempt at a Solution I understand the duration of time it takes to go up the hill is a larger time...

A simple computational question, that I saw in a journal article and have been having trouble getting. Define the variable V (implicitly) by: V=b + \int^{rV}_{0} rV dF(s) + \int^{\infty}_{rV} s dF(s), where r is a constant and F has support on [0,∞). Question: Show that...

Okay, this is not a homework problem, and I think if I really played with it long enough I could work something out. But really, I just want an answer, so I'm hoping someone on here who really loves solving problems like this can just knock it out. It would be much appreciated. I'm wondering...

Dear All, I started to look around for a reliable definition of the differences between Calculation, Computation and Simulation, but I'm not satisfied with what I've found. In your view, what are the correct usages of these terms? When something becomes more than a computation or calculation...