Standard Definition and 1000 Threads

There has been a lot of talk about the value of beauty in theoretical physics. There seems to be a lot of little things that are beautiful because they make sense, according to what we already know, like the discovery of anti-particles, and recently the Higgs. The standard model was revealed...

Title says it all. Maybe it belongs more in Astrophysics but given the title... "Beyond the Standard Model Explanations of GW190521" - - - - https://arxiv.org/abs/2009.01213 If this is for real I'm surprised it's gotten so little attention..? EDIT PS: (for my own convenience mostly) ...

I can't help but feeling these days that I don't actually understand where most of the maths I use comes from. Unfortunately, I can't remember whether this is due to the fact that I didn't take my studies seriously until the end of undergrad, or rather that these things were never actually...

I guess the crux of the question is, where are we more likely to encounter new physics? The standard model already explains almost every experimental result, but not EVERY result. But what are some of the most important results that are either incompatible with the standard model or just...

[Throughout we're considering the intrinsic version of the covariant derivative. The extrinsic version isn't of any concern.] I'm having trouble reconciling different versions of the properties to be satisfied by the covariant derivative. Essentially ##\nabla## sends ##(p,q)##-tensors to...

In many physics curricula, some elements of the so called "old" (Bohr-Sommerfeld) QM are taught before teaching the actual QM. The pedagogic value of such teaching may be doubtful, but for someone without prior knowledge of QM, the old QM is more intuitive than the actual QM. That's because the...

Summary:: Is there a primarily non-technical book covering all aspects of the Standard Model of particle physics? The Standard Model comes up a lot in YouTube videos. There must be a decent amount of public interest. I think there would be a market for a semi-technical but accessible for the...

Hi. I'm looking for recommendations of books, surveys, or lecture notes, that deal with physics beyond the standard model all in one place. The starting point is someone who already knows QFT and the SM at the level of Schwartz's book on QFT and the SM...

I thought this might be worth a read: https://iopscience.iop.org/article/10.1088/1361-6552/aa5b25/pdf

I read that confidence interval on standard deviation can be found using chi-square distribution. If I have a sample size N=500, and sample standard deviation= 3 with mean=0, and I need a 95% confidence, I wasn't sure what to set for degrees of freedom in chi-square formula. Is the degrees of...

They seem to have something to do with Z or W particles, maybe, and they have something to do with mediating weak iso spin, I think, and they may be related to the Higgs field. But they don't have a box dedicated to them on the Standard Model of particle physics. Can someone tell me why this is...

Unflued gas appliances emit all of their combustion products into the room in which they are installed. In the UK, ambient carbon dioxide in the commercial workplace is limited to 2800 ppm. The UK/European standard BS EN 13410 (and many appliance manufacturers) give the formula for mechanical...

This is just a quick alert regarding a paper today https://arxiv.org/abs/2005.03048 Exceptional Unification of Families and Forces Alfredo Aranda, Francisco J. de Anda, Stephen F. King [Submitted on 6 May 2020] This work considers the remarkable suggestion that the three families of quarks and...

We're working on a project that plots flux density of a light curve with respect to time. To do this, we had to scale data from different wavelengths so we had just the one variable for the flux. Essentially we took each value for flux density and multiplied it by three over the frequency raised...

#include<stdio.h> #include<math.h> double foo(int n, int mean){ double square; if(n==1){ return(1); } if(n!=0){ square=pow(n-mean,2); return( (sqrt(square)+foo(n-1,mean))/(sqrt(n-1)) ); }} int main(){ int num; double mean; int i; int...

I enjoy music and have acquired a certain level of relative pitch. That is, I attempt to be able to identify musical intervals and chords such that I can play along with the music that I'm listening to. The guitar is a good instrument for me because of its simple layout . However, piano has...

The syllabus states : "Explain that the potential difference which is needed to apply across any electric circuit to flow current is supplied by an electric source". To explain this and make notes, I want to first understand what an electric source particularly is. And how all those electric...

Sometimes I hear particle physicists refer to left/right chiral electrons as different particles that are 'mixed' by the mass term. Maybe I misunderstood entirely, but if there is even a handwavy sense in which this is the case, clarifications would be appreciated. In high energy collisions...

Building jig for a project, trying to think of ISO that would apply. So far i got ISO 8888 ISO 10377 ISO 14990 ISO MADECan somebody help

Hey there, I was looking at the Higgs sector of the standard model, particularly its coupling to the fermions: ##\mathscr{L}_{ yukawa }=-\sum _{ a,b=1 }^{ 3 }{ \left( { Y }_{ ab }^{ u }{ \bar { Q } }_{ a }{ \hat { \varepsilon } }_{ 2 }{ H }^{ \dagger }{ u }_{ b }+{ Y }_{ ab }^{ d }{ \bar { Q }...

Why do we take ISA conditions(Atm. Temperature, Atm. Pressure) as static and not stagnation? Thanks

Using the above formulas, we can arrive at an unbiased estimate of the standard deviation of the sample, then divide by sqrt(N) to arrive at the standard deviation of the average. What I'm confused about it where the measurement uncertainty comes into the equation. Is it being ignored? Say I...

When designing a panel, it is imperative that you keep the components inside at a temperature which they can operate optimally at; allowing the air temperature to go above this limit can cause component failure and fire. To assist with calculating the air flow required to keep the components...

how would the year 2011 appear in standard form

The standard answer: “In GR, only average density matters.” That is what Friedmann’s equations (1) say—mathematically—but he does not derive that conclusion. He starts with it. Friedmann does not start with a messy, real-world model of the universe, one that has fractured into galaxy clusters...

Just a curious question, is there a limit within the standard model on how many fundamental forces there can be? I have some familiarity with particle physics/QFT(not quite mastery obviously otherwise Id probably be able to answer this myself) and the thought popped in my head when reading about...

The expression I have found is this one. https://ibb.co/kqG24L3 I have been looking for information because I could not to realize what is the value that "alpha" has to have. If any of you do know what this alpha value is supposed to represent or if you have seen it before I would be really...

I am doing a research project about Hubble tension. Even if I have some ideas about how we measure the $$H_0$$ by using the standard candles, i don't have much knowledge about it. I suppose we are measuring the luminosity distance and then by dividing it (1+z) to get the proper distance and...

Excuse me, I am not too well versed in statistics. I am in engineering. Let's say I have an expected measurements(grand mean of values) and then I take another measurement of two different samples. Each sample is measured a few times to get it's own standard deviation and expected value. I...

The T^0i the components of the energy momentum tensor that correspond to mass flux and/or momentum density. If I wanted to get standard units of flux I would just multiply by c^2 correct? It is the ith component of momentum across the kth surface? I am thinking of an example in particular that...

In the article https://medicia.ru/en/immunoterapiya-pri-lechenii-raka-immunoterapiya-chto-nuzhno/, terms such as "autopiotherapy" are used which Google does not give elsewhere. Many legitimate standard terms, of course, are not known to Google. But I did not find, for example, "autopiotherapy"...

I am watching a show about the Standard Model and The Theory of Everything (which of course we do not have right now) and the lecturer mentioned gravity is not part of the Standard Model. Yet other books include it. What is the general consensus? Thanks Bill

On the premise that gravity transcends time, is there any reason that the effects of gravity that we observe as dark matter simply be the effects of gravity from the mass of standard matter from the past? For example the mass of our galaxy may not be enough to explain the effects of gravity...

I am curious about the standard enthalpies of formation of carbon nanotubes, diamond, carbon buckyballs, graphene, etc. I read from physics forums that the standard enthalpies of formation of these allotropes of carbon are small. However, since diamond is fabricated naturally under extreme...

I am currently reading Griffiths Introduction to Quantum Mechanics, 2nd Edition. I am aware that, in light of considering potential functions independent of time, the Schrödinger equation has separable solutions and that these solutions are stationary states. I am also aware (If I stand correct)...

Consider a pair of entangled particles described by a local theory without hidden variables. Because there are no hidden variables, the results of an experiment on one particle of the entangled pair must be perfectly random. Due to locality, the particles also have no way of coordinating the...

Hi, I don't know much about the standard model but I'm asking out of interest. Why do we actually need a Lagrangian for the standard model? Surely when you apply the relevant Euler-Lagrange equations, you end up with a variety of equations like the Maxwell equations or Dirac equations. Why...

I have a data set 1st coloumn containing ##x## values 2nd coloumn containing ##y## values and 3rd coloumn containing standard deviation of ##y## associated with each ##x## value...I want to plot these 3 values together in a MATLAB plot...can anyone please help me in this regard??

Below is the spreadsheet image. The source of the data in the two columns, Ho and +/-, is the following article http://planck.caltech.edu/pub/2015results/Planck_2015_Results_XIII_Cosmological_Parameters.pdf . Let AHo be the conjoined weighted average values for Ho and the corresponding error...

I came across this basic limits question Ltx->0[(ln(1+X)-sin(X)+X2/2]/[Xtan(X)Sin(X)] The part before '/'(the one separated by ][ is numerator and the one after that is denominator The problem is if I substitute standard limits : (Ltx->0tan(X)/x=1 Ltx->0sin(X)/X=1 Ltx->0ln(1+X)/X=1) The...

I know that standard deviation of whatever data is defined as sqaure root of square difference from mean value: ##\sigma(data)=\frac{\sum_{x \in data}((x-x_{mean\ of\ data})^2)}{|data|}=\frac{\sum_{x \in data}((x-\sum_{y \in data}(y)/|data|)^2)}{|data|}## but sometimes formula...

At equilibrium, we know that deltaG = 0. But what about deltaG_zero, i.e. the standard Gibbs free energy? When is deltaG_zero = 0? In the solution manual it says that it means that K = 1, but by calculating an equilibrium constant you are already stating that we are at equilibrium? I.e. that...

I want to estimate the parameters and standard errors of the following ARMA/GARCH model: ##y_t=a+b y_{t−6}+cy_{t−8}+dϵ_{t−1}+ϵ_t## ##σ^2_t=ω+αϵ^2_{t−1}+βσ^2_{t−1}##The code I use is: def main(): x0 = (0.01,0.01,0.01,0.01,0.01, 0.01, 0.01) b = minimize(garch_loglike, x0, R_bel, bounds...

I'm revising for my condensed matter exam, and I've never understood the point group notation, in particular of the 32 crystallographic point groups, so let me try and explain what I understand of it and point out where my confusion lies. Please point out any other misunderstandings I have. We...

+(3/2) standard deviations from the mean = \frac {a+b}{12} + \frac{\sqrt3}{4} (b-a) -(3/2) standard deviations from the mean = \frac {a+b}{12} - \frac{\sqrt3}{4} (b-a) \frac {1}{b-a} \int_a^{\frac {a+b}{12} - \frac{\sqrt3}{4} (b-a)} dx = m_1= \frac {(-11+3\sqrt3)a + (1-3\sqrt3)b}{12(b-a)}...

In the quantum mechanics of covalent bonding, there are two competing theories: https://en.wikipedia.org/wiki/Covalent_bond#Comparison_of_VB_and_MO_theories Both are complementary, but they don't overlap fully, they still leave some gaps.What I want to ask is, can all the literature of the...

Hi, I want to program an GARCH model for exchange rates. To do this, I calculated the residuals. Next, I did the following (in python) def main(): vP0 = (0.1, 0.05, 0.92) a = minimize(garch_loglike, vP0, eps, bounds = ((0.0001, None), (0.0001, None), (0.0001, None))...

Hi All, I need to figure out the definition of the oft-called "Standard" action of the circle ##S^1 ## ( as a Topological/Lie group) ,on ##S^n##, the n-sphere ( I guess seen as ##\{z : |z|=1\}## in Euclidean n-space). My searches returned an action of ##S^1## on ##S^3 ## given by ##A(z_1...

https://arxiv.org/pdf/1903.00009.pdf "We present an explicit construction of O(1015) globally consistent string compactifications that realize the exact chiral spectrum of the Standard Model of particle physics with gauge coupling unification in the context of F-theory. Utilizing the power of...

Sorry, I'm not an astronomer. This question relates to the book "S." by Doug Dorst. I understand that the celestial coordinates have a zero-point at the vernal equinox. (0h, 0m, 0s RA, 0⁰, 0", 0' Dec.) I also understand that it's possible to map these coordinates to spherical, or...