What is Atlas: Definition and 63 Discussions

An atlas is a collection of maps; it is typically a bundle of maps of Earth or a region of Earth.
Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geographic features and political boundaries, many atlases often feature geopolitical, social, religious and economic statistics. They also have information about the map and places in it.

View More On Wikipedia.org
  1. kimi7335

    I Distribution of satellite clusters around seed cluster in ATLAS

    From data of proton-proton collisions at the LHC using the ATLAS detector I have plotted a heatmap of the distribution of satellite clusters (brem and converted photons) around seed clusters (electron/photon candidates without satellites) at (eta, phi) = (0,0). The data I am using is of the...
  2. kimi7335

    I The purpose of trigonometric axes in plot of electron clusters, ATLAS

    I have been doing some reading on electron reconstruction from proton-proton collisions at CERN. In some of the papers I have read, plots such as the one In the figure are included. What I would like to know is why they have chosen to plot the x and y axes as cos(phi) * tan(theta) and sin(phi) *...
  3. cianfa72

    I ##SL(2,\mathbb R)## Lie group as manifold

    Hi, consider the set of the following parametrized matrices $$ \begin{bmatrix} 1+a & b \\ c & \frac {1 + bc} {1 + a} \\ \end{bmatrix} $$ They are member of the group ##SL(2,\mathbb R)## (indeed their determinant is 1). The group itself is homemorphic to a quadric in ##\mathbb R^4##. I believe...
  4. ohwilleke

    I The Latest Higgs Boson Mass Measurement

    The current Particle Data Group global average measurement for the Higgs boson mass is 125.25 ± 0.17 GeV. The previous combined ATLAS Higgs boson mass measurement (via the Particle Data Group) was 124.86 ± 0.27 GeV from 2018 (using Run 2 data), and the previous combined CMS Higgs boson mass...
  5. ohwilleke

    I New Constraints On The Higgs Boson Width

    The New Measurement The ATLAS experiment at the Large Hadron Collider (LHC) has experimentally limited the "width" of the Standard Model Higgs boson with a rest mass of about 125 GeV to 4.5 + 3.3 - 2.5 MeV, with a maximum value of 10.5 MeV at a 95% confidence level. In the Standard Model, the...
  6. mfb

    A ATLAS reanalysis of W mass: Lower uncertainty, agrees with SM

    Improved ATLAS result weighs in on the W boson Same dataset, but better analysis methods and some new results from elsewhere that could be used. Money plot from ATLAS: This makes the CDF measurement an even weirder outlier than it was at the time of publication.
  7. GaNHEMT

    Silvaco Atlas Syntax question - area from curve

    I have a several questions on the following block of codes taken from ganfetex01_aux.in: solve save outf="ganfetex01_$'index'.str" extract init inf="ganfetex01_$'index'.str" extract name="2DEG" 1e-4 * area from curve (depth, impurity="Electron Conc" material="All" mat.occno=1 x.val=0.5) \...
  8. davenn

    Stargazing ATLAS observations of the DART spacecraft impact at Didymos

    Astronomers with the ATLAS project also chronicled the event. Short for Asteroid Terrestrial-impact Last Alert System, ATLAS is an asteroid impact early warning system based in Hawaii and funded by NASA. “ATLAS observations of the DART spacecraft at Didymos” exclaimed ATLAS in a tweet. A...
  9. A

    I Constructing an Oriented Atlas for S1 (Self Study)

    Hello, I am trying to construct an oriented atlas for S1 by considering the 8 transitions from the basic coordinate projection atlas. However, it does not appear to be possible to modify this atlas without destroying existing progress. Am I on the right track towards constructing the oriented...
  10. H

    For those who use Atlas Silvaco

    if someone who uses Atlas Silvaco can send me the file organicex09_aux.in which is an example in the library of atlas2021 thanks
  11. Dive into ATLAS at CERN for the Global Science Show

    Dive into ATLAS at CERN for the Global Science Show

    Introduction to the research at ATLAS at the LHC
  12. mfb

    I ATLAS and CMS see signs of Higgs->muons decay

    The Higgs boson couples to mass, muons are relatively light, that makes a decay to a pair of muons (muon+antimuon) very rare. In addition there are many other processes that produce pairs of muons, making this decay mode challenging to find. For a long time it was expected that the experiments...
  13. S

    B How to select the smooth atlas to use for spacetime?

    I'm studying differential geometry basics for general relativity (no specific source, just googling around). I know that spacetime is modeled as a ##4##-dimensional smooth manifold. Smooth manifold means that we consider a restriction of the maximal atlas such that all charts in it are...
  14. A

    I What is an atlas for a torus manifold?

    I don't quite understand some work I'm doing creating the normal Riemann surface for the function ##f(z)=\frac{A}{\sqrt{(1-z^2)(k^2-z^2)}}##. I can use Schwarz-Christoffel transforms to map the function to a rectangular polygon in the zeta-plane then map this rectangle onto a torus. But I...
  15. ohwilleke

    I Is the new 3.0 TeV bump at ATLAS a fluke?

    The ATLAS experiment has seen a bump that could be a new particle at a mass of 3.0 TeV/c^2 with a local significance of more than three sigma, and a global significance of a bit more than two sigma in Run-2 data looking at decays of qqbb states to a W or Z boson and a Higgs boson. It is...
  16. J

    I Difference between CMS and ATLAS wrt channels

    I was wondering what the differences are between CMS and ATLAS when it comes to their channels. I know they detect for the H →γγ, H → 4l, H → eνμν channels, but I was wondering how they differ in their detection for these channels. I was also wondering if there were any noticeable...
  17. BillTre

    Cloud Atlas (not the movie) Gets an Update

    Newly described clouds (also here) have been added to the International Cloud Atlas. I have always found clouds kind of fascinating, especially when viewed from airplanes. Didn't even know there was a cloud atlas.
  18. D

    Is There a Physics Equivalent to Math-Atlas.org?

    Hello everyone. I have been a lurker for a while and i finally decided to join the forum. So here's my question: "Is there anything similar to math-atlas.org?" For those of you that don't know Math-Atlas is a website that tries to pin down all of the mathematical branches and present them in a...
  19. BillTre

    Geologists Uncovering the Earth's History with Subducted Slabs

    It seems that geologists are becoming more able to visualize subducted slabs. They hope to be able to unwind the tape of Earth history, to some extent, (like 250 million years).
  20. mfb

    I Evidence of Light-by-light scattering by ATLAS

    For centuries, scientists argued whether light was waves or particles. Light scattering with other light would favor the particle concept. Today we know both models are wrong, but quantum electrodynamics also predicts this scattering - just with an incredibly tiny rate, so it has never been...
  21. ChrisVer

    I Just how long is the ATLAS detector?

    A question that actually makes me laugh, but ... how long is the ATLAS Detector? Based on the ATLAS page here: http://atlas.cern/discover/detector the detector is 46m long. Based on references like here: http://arxiv.org/pdf/0910.3081.pdf the detector is 44m long. I wouldn't have asked this if I...
  22. mfb

    I New LHC Results 2015: Interesting Diphoton Excess?

    https://www.physicsforums.com/threads/new-lhc-results-2015-tuesday-dec-15-interesting-diphoton-excess.84798 and status from Monday CMS released their conference note a bit earlier. They see absolutely nothing at the mass range where the excess appeared in 2015. It is a bit curious that they...
  23. orion

    I Understanding the Transition Functions for S^1 Using Atlas Charts

    I am confused about the procedure for finding the transition functions given an atlas. I understand the theory; it's applying it to real life examples where I have my problem. So for example, take S1 (the circle). I want to use 2 charts given by: U1 = {α: 0 < α < 2π} φ1 = (cos α, sin α) U2...
  24. Safinaz

    I Interpreting CMS and ATLAS results

    Hi all, Any help about interprting the results of ## \sigma(pp \to H) \times BR (H \to WW) ## mentioned in Fig.(12-13) in [arXiv:1509.00389[hep-ex]]? In that paper [arXiv:1512.06728v3[hep-ph]], page 8, its said that according to these figuers ## \sigma ( pp \to H \to WW^* )\leq 54, 37 fb...
  25. ChrisVer

    A Track Reco in the Inner Detector of ATLAS

    I was reading about track reconstruction. So, I read about the "inside-out" and "outside-in" strategy for track reco. However both those strategies utilize information coming from the InDet parts... I know though, that the Muon Chambers are also used for the track reconstruction in ATLAS. How is...
  26. ChrisVer

    A Resolutions of ATLAS Detectors

    Hi, I was looking for ATLAS detector parts resolutions (momentum for Inner Detector and Energy for the CAL systems). Does anyone have a nice reference? So far I found something like this for the ID: \sigma_{1/p_T} = 0.34 \text{TeV}^{-1} \Big(1 \oplus \frac{44 \text{GeV}}{p_T} \Big) With...
  27. Greg Bernhardt

    Atlas, next gen robot from Boston Dynamics

    Some really impressive movement!
  28. A

    3D simulation of Cone in Atlas Silvaco TCAD

    Hi I am interested in simulating the a cone structure in Silvaco's ATLAS TCAD. Since its has a cylindrical symmetry, I should be able to define a simple triangle and rotate it about a side to form the cone. I am not sure if this facility is available in Silvaco, like in Sentaurus from...
  29. mfb

    New LHC results 2015: Tuesday Dec 15 - interesting diphoton excess

    After a slow start, the LHC and its detectors worked nicely and collected a lot of data this year (~3.5/fb). While many analyses are still ongoing, both ATLAS and CMS will report several results on Tuesday 3 pm (CET)*. The presentations will probably appear here, a...
  30. ChrisVer

    ATLAS inclusive and sliced samples (eg W+jets)

    I have a small technical question, if anyone has ever worked with it... What does inclusive and sliced samples mean (at a MC generator)? I have seen that the sliced samples are divided according to mass slices for the different processes, but the inclusive are not. Why would they give such...
  31. F

    Mathematica Is anyone familiar with using Atlas 2 for mathematica?

    Is anyone familiar with Atlas 2 for mathematica to calculate the Riemann Tensor, Ricci Tensor, and scalar I have a metric that I need to calculate these things for. Can anyone help? I'm not too up on Mathematica either.
  32. ChrisVer

    Understanding Tau Identification in ATLAS: A Brief Overview

    I have some questions concerning this paper (mainly about the tau identification): http://arxiv.org/pdf/1201.5466v1.pdf especially the figures 3-6... I don't understand what is the inverse background efficiency, neither the likelihood score. As a result, I am unable to understand what info the...
  33. G

    Constructing an Atlas for ##S^2## with Spherical Coordinates

    Now, this is kind of embarrassing, but I've been trying to do this for too long now and failed: I want to construct an atlas for ##S^2##, but I want to use spherical coordinates rather than stereographic projection. Of course the first chart image is simply ##\theta \in (0, \pi), \varphi \in...
  34. gracy

    Atlas 66: Improving Cultivated Wheat Through Donor Selections

    Atlas 66 has been used as a donor for improving cultivated wheat.what does this mean?MY attempt-Atlas 66 is a cultivar i.e a plant variety that has been produced in cultivation by selective breeding.so it contains desired characters such as more than one Al tolerance gene .so plant breeders can...
  35. Spinnor

    Atlas of torus and sphere. Atlas of Calabi–Yau manifold.

    Is it true that the atlas for a torus can consist of a single map while the atlas for a sphere requires at least two maps? Can we ever get by with a single map for some Calabi–Yau manifolds assuming that question makes sense? If not is there some maximum number required? Thanks for any help!
  36. ChrisVer

    Muon Interaction at ATLAS Hadron Calorimeter: Investigating Energy Dependence

    Can actually muons interact and give a signal while they go through the Hadron Calorimeter of the ATLAS? I think in general this isn't impossible, but it should depend on the muon energy... I would like to see that energy dependence, even quantitatively.
  37. $

    Silvaco Atlas export Energy Band Diagram programatically

    Hi, I perform my post-processing and analysis of data from silvaco in MATLAB and would like to export values from the .str file to a file that can be read easily into matlab. Does anyone know of a way to do this programmatically? I can do it in tonyplot, but I've got everything else scripted...
  38. B

    Global Coord Atlas Universe: GR Coord Charts, Speed Light

    I am wondering how big the local coordinate charts in a coordinate atlas of General Relativity can be. Is it just a few nanometres or all the way to the furthest stars? Also I wonder how the speed of light is defined in GR. Is the velocity defined as the differential with respect to coordinate...
  39. B

    Constructing Atlases: Understanding Topology for GR Class

    I'm trying to get a better understanding of some topology for a GR class I'm taking...I'm wondering if someone can help me understand how to go about constructing atlases or just charts in general. I understand the concept but I am trying to get a better handle on the math.
  40. B

    Device simulation with Silvaco ATLAS

    How can I give interface traps while simulating a power MOSFET in Silvaco ATLAS tool?
  41. K

    Could anyone help me to recognize the Atlas results?

    Hallo, Dear particle physicist, Despite I am major in biophysics, the particle physics looks attractive to me... So I just used Atlantis to check some experiments result from internet... Although I can find some resultant particles. I still cannot understand how to draw a Feynman diagram for...
  42. K

    Atlas of complex projective 3-space ##\mathbb{C}P^3##

    I'm constructing an atlas for complex projective 3-space ##\mathbb{C}P^3##. I use the construction with inhomogeneous coordinates ##z_{i}/z_{j}## and a chart is given by the points ##\mathcal{U}_j=\{z_j\ne 0\}##. At the intersections ##\mathcal{U}_i\cap \mathcal{U}_j## I should specify...
  43. T

    Silvaco IC simulation with Athena Atlas

    I have a question about silvaco athena && atlas simulation, MOS structure, when I gate length is 0.6um, get Vth is 1.8V, but I only change gate length to 0.55um, get Vth is 1.6V, it's a error data I know, but I do not know why, what wrong with the program, how can I change it. would you please...
  44. I

    How Can You Prove an Atlas Is Maximal?

    I've been looking in various books in differential geometry, and usually when they show that a smooth manifold has a differentiable structure, they just show that the atlas is C^\infty compatible, and forget about showing it is maximal. Which got me thinking. Given an atlas, how DOES one show...
  45. F

    Admiring the ATLAS LEGO Model: Not for 2000 Euro!

    I want one! ... well maybe not for 2000 euro: http://sascha.mehlhase.info/media/ATLAS%20LEGO%20model/2011-11-10%2010-21-41%20ATLAS%20LEGO%20model.jpg http://sascha.mehlhase.info/media/ATLAS%20LEGO%20model/2011-11-08%2011-06-31%20ATLAS%20LEGO%20model.jpg...
  46. G

    Differential geometry: smooth atlas of an ellipsoid

    Homework Statement Consider the ellipsoid L \subsetE3 specified by (x/a)^2 + (y/b)^2 + (z/c)^2=1 (a, b, c \neq 0). Define f: L-S^{2} by f(x, y, z) = (x/a, y/b. z/c). (a) Verify that f is invertible (by finding its inverse). (b) Use the map f, together with a smooth atlas of S^{2}, to...
  47. C

    Si Bandgap in Device Modeling (Silvaco Atlas)

    I recently noticed that in Silvaco Atlas (device modeling software), the default bandgap of silicon is given as 1.08 eV. This is at 300 K, no bandgap narrowing, and no other secondary effects - it is default. However, most (all?) of the modern references (e.g. Sze, Streetman, Pierret) give the...
  48. J

    What are the conditions inside the LHC Atlas detector?

    If I could be inside the LHC Atlas detector during a proton bean collision what would I see? Would there be a huge flash of light? Would I be killed, if yes how fast? Or would there be nothing to see?
  49. J

    Review: Atlas Shrugged: Part 1 Movie

    I just saw the film Atlas Shrugged: Part 1. Here are my thoughts. First of all about the book. I agree with the philosophic stance. No one should be forced to live for another. In my career, I never worked for free. I always charged for my services in the form of wages. This is as it should...
  50. L

    Manifold / Atlas / Chart (Building Simple Example)

    I’m studying GR and am curious about manifold, atlas and charts. I have an idea for building a simple example, in one dimension, and wanted to ask if what I’m doing below is “legal”/correct. Imagine a space flight that can be divided into three segments: A-B: velocity starts at zero and...