Cyclic Definition and 309 Threads

  1. maverick_starstrider

    Relativistic angular momentum and cyclic coordinates

    I'm getting myself confused here. If my relativistic Lagrangian for a particle in a central potentai is L = \frac{-m_0 c^2}{\gamma} - V(r) should \frac{d L}{d \dot{\theta}} not give me the angular momentum (which is conserved)? Instead I get \frac{d L}{d \dot{\theta}} = -4 m...
  2. M

    The Cyclic Universe: A Theory of Formation and Evolution

    To begin, and believe me, it will become apparent, I have no training or education in this field. I do however find it fascinating. Can someone with a greater understanding please tell me if my ideas are laughable or feasable? Has anybody else proposed these ideas? Okay, so...
  3. P

    Proving Cyclic Quadrilateral: Opposite Angles Sum 180°

    Homework Statement I have got a question that might be easy for you. But, not for me. I have attached a pic. Please tell me if the quadrilateral inside the circle is a cyclic quadrilateral or not. If it is, then please explain how to prove that it's opposite angles sum up to 180 degrees...
  4. K

    Axisymmetric vs cyclic symmetry boundary conditions

    Hi, Can anyone explain the difference between axisymmetric and cyclic symmetry boundary conditions? Isn't it the same i.e. bith cyclic symmetry and axisymmetric?
  5. S

    Vibration analysis of a structure with cyclic symmetry

    Lets us say we are doing a vibration analysis of a structure with cyclic symmetry In very brief (as pointed out by AlephZero in one of his excellent reply) the whole motion can be represented by complex numbers which describe the motion of one segment. Now, my question is: 1)Is it...
  6. H

    Is time linear or cyclic in a flat, zero energy universe?

    I'm writing a paper for a philosophy elective on the Cosmological argument. One of my counter arguments is that a causal loop (treated as a paradox in the Cosmological argument in favor of a creator) is not a paradox if time is cyclic in nature rather than linear. I treat the fact that the...
  7. S

    What is Cyclic Symmetry in Jet Engines?

    Hi, Please can anyone explian what is cyclic symmetry? I'm new to this term and have encountered this in jet engine example Vishal
  8. L

    External direct products of cyclic groups

    I'm wondering if anyone can help me with learning how to write groups as an external direct product of cyclic groups. The example I'm looking at is for the subset {1, -1, i, -i} of complex numbers which is a group under complex multiplication. How do I express it as an external direct...
  9. T

    Does k Divide R's Order When R's Additive Group is Cyclic?

    If R is a finite ring and its additive group is cyclic, then R = <r> = {nr : n an integer} for some r in R. r^2 is in R so r^2 = kr for some integer k. Does k have to divide the order of R?
  10. Z

    Calculate Diffusion Coefficient K4Fe(CN)6 Cyclic Voltammetry

    Homework Statement Calculate the diffusion coefficient (cm2/s) of ferricyanide if cyclic voltammograms conducted on a solution of 1 mM KClO4 + 5 mM K4Fe(CN)6 at scan rates of 1, 2, 5, 10, 20, and 50 mV/s, resulted in peak currents of 76, 100, 175, 243, 348 and 552 mA. The electrode used for...
  11. L

    Why do so many people claim cyclic models brake down due to entropy?

    To my intuition, I find more easy to believe that the universe is infinitely old and the big bag was just one of an infinite number of similar events in a larger universe, rather then the universe had a beginning. However, after watching many documentaries, and reading a lot of popular...
  12. E

    Prove product of infinite cyclic groups not an infinite cyclic group

    Homework Statement Show that the product of two infinite cyclic groups is not an infinite cyclic? Homework Equations Prop 2.11.4: Let H and K be subgroups of a group G, and let f:HXK→G be the multiplication map, defined by f(h,k)=hk. then f is an isomorphism iff H intersect K is...
  13. I

    Proof of Cyclic Subgroup Equivalence for Finite Groups

    Homework Statement Suppose a \in <b> Then <a> = <b> iff a and b have the same order (let the order be n - the group is assumed to be finite for the problem). Proof: Suppose a and b have the same order (going this direction I'm trying to show that <a> is contained in <b> and <b> is...
  14. L

    Showing the unit group is cyclic

    Homework Statement Let p be a positive prime and let Up be the unit group of Z/Zp. Show that Up is cyclic and thus Up \cong Z/Z(p − 1). The Attempt at a Solution What do they mean by the unit group? Is that just the identity? Is it the group [p]? I'm lost without starting the question...
  15. B

    Abstract Algebra - Cyclic groups

    1. Problem: Suppose a is a group element such that |a^28| = 10 and |a^22| = 20. Determine |a|. I was doing some practice problems for my exam next week and I could not figure this out. (This is my first post on PF btw) 2. Homework Equations : Let a be element of order n in group and let k...
  16. B

    Cyclic Universe - Fixed in Size but Divided into 8 Sections

    What is wrong with assuming a fixed size universe, dividing it into 8 octants, and allowing the various octants to expand and contract against each other? In such a situation, could our octant be currently expanding and due to the pressure of our expansion cause one or more adjacent octants to...
  17. J

    Cyclic Fusion Reactor_Colliding Beams_Final Edition

    Cyclic Fusion Reactor_Colliding Beams_Final Edition PDF file
  18. S

    Proof that a certain group G contains a cyclic subgroup of order rs

    Homework Statement Let G be an abelian group and let H and K be finite cyclic subgroups with |H|=r and |K|=s. Show that if r and s are relatively prime, then G contains a cyclic subgroup of order rsHomework Equations Fundemental theorem of cyclic group which states that the order of any...
  19. K

    How Does the Cyclic Decomposition Theorem Simplify Matrix Analysis?

    I took an Intermediate Linear Algebra course all last year (two semesters worth) and we covered the CDT. My professor didn't teach it well, and I got my first B- in university because of it (didn't affect my GPA but still irritating). I didn't understand a lot of the canonical form stuff...
  20. P

    Is the group of permutations on the set {123} Cyclic? Justification required

    Homework Statement Consider the group of permutation on the set {123}. Is this group cyclic? Justify your answer Homework Equations The Attempt at a Solution I wrote out the cayley table for this group, and noticed that if we take (123)^3 = e . Seeing as we can get back to the...
  21. Z

    Proving a Group is Cyclic: What is the Generator of G?

    Homework Statement For each integer n, define f_{n} by f_{n}(x) = x + n. Let G = {f_{n} : n \in \mathbb{Z}}. Prove that G is cyclic, and indicate a generator of G. Homework Equations None as far as I can tell. The Attempt at a Solution Doesn't this require us to find one element of G such...
  22. K

    Composition length of cyclic groups.

    Homework Statement Let G be a finite cyclic group and \ell(G) be the composition length of G (that is, the length of a maximal composition series for G). Compute \ell(G) in terms of |G|. Extend this to all finite solvable groups. The Attempt at a Solution Decompose |G| into its prime...
  23. B

    Classes of polynomials whose roots form a cyclic group

    Hi, I'm currently doing a project and this topic has come up. Are there any known famous classes of polynomials (besides cyclotomic polynomials) that fit that description? In particular, I'm more interested in the case where the polynomials have odd degree. I know for example that the roots of...
  24. J

    Cyclic Fusion Reactor. Passing through each other colliding beams.

    Recently I have placed here the new - viable by my opinion Concept how to produce fusion. By some reasons I have decided not to file the patent application and so for discussing now I am placing here the description of Cyclic Reactor on base of that Concept. Ioseb (Joseph) Chikvashvili
  25. C

    Can the New Cyclic Model Revolutionize Our Understanding of the Universe?

    I do not have any mathematical proof of this being possible, but am hoping to include equations soon. For now, it is purely conceptual. According to the Steinhardt-turok model, our universe is on a 3-brane located next to another 3-brane. I will assume this is the case. I am also presuming...
  26. S

    Finding U13 Cyclic Numbers: A Faster Way?

    Homework Statement Is U13 cyclic? The Attempt at a Solution I know the elements are {1,2,3,4,5,6,7,8,9,10,11,12}. I have eliminated 1,2,3,4,5 and I am working on 6. I am doing it this way: 60=1 61=6 62=10 63=8 64=9 65=2 ..and so on, but I did, for example, 62=36-13=23=10...
  27. Y

    Is the Product of A and An in a Cyclic Group of Order n Outside the Group?

    Given a cyclic group of order [FONT="Georgia"]n, with all its elements in the [FONT="Georgia"]form : A, A2, A3, ..., A[FONT="Georgia"]n where A is an arbitrary element of the group. According to the [FONT="Georgia"]definition of group, "The product of two arbitrary elements A and...
  28. F

    What Do Standby and Cyclic Use Ratings Mean for Batteries?

    I've been doing a project recently that requires a UB1250ZH Universal Battery rated 12V and 5Ah. Although I understand the concept of Ah, I'm having a difficult time in figuring out what the ratings for standby and cyclic use mean. For an example, it says - Standby Use: 12.6-13.8V, the...
  29. Z

    Why is the Integer Group Z Considered Cyclic?

    This might sound like a silly question, but based on Definition: A group G is called cyclic if there is g\in G such that \langle g \rangle = G And if we take (\mathbb{Z},+) the set of integers with addition as the operation, then why is it considered cyclic? Because the problem I am having...
  30. D

    Cyclic Compounds: Which Shape is the Most Stable?

    Homework Statement C3H6 cyclopropane C4H8 cyclobutane C6H12 cyclohexane Looking at their bond angles, which do you think is most stable? The Attempt at a Solution I'm trying to examine their shapes - triangle, sqaure and hexagon, but I don't know which shape is more stable...
  31. marcus

    Latest Penrose video on Conformal Cyclic Cosmology

    http://pirsa.org/11040063/ Big Perimeter audience, appreciative interest, long question period after. He undercuts his critics (who said the concentric circles could have appeared by chance) by criticising their methods and makes at least one valid point. I would say that the critics still...
  32. C

    Cyclic Subgroups in Symmetric and Cyclic Groups

    Suppose K= < x > is a cyclic group with 2 elements and H= S3 is symmetric group with 6 elements. Find all different cyclic subgroups of G= H x K. Now since K is generated by x with 2 elements, I have K= {1,x} and H= {1, (12), (13), (23), (123), (132)} What I am confused about is finding...
  33. B

    Abstract Algebra and cyclic subgroups

    Homework Statement from Algebra by Michael Artin, chapter 2, question 5 under section 2(subgroups) An nth root of unity is a complex number z such that z^n =1. Prove that the nth roots of unity form a cyclic subgroup of C^(x) (the complex numbers under multiplication) of order n...
  34. D

    Cyclic Universe, Big Rip version

    I wonder if someone has ever considered the following scenario: 1. "Standard" Big Rip model (phantom energy-dominated) 2. Close to the Big Rip, Universe becomes crossed with Cosmological horizons 3. Based on semiclassical approach, these horizons emit Hawking radiation 4. As a (slightly...
  35. M

    |G|=4. Prove the group is either cyclic or g^2=e

    Let G be a group with |G|=4. Prove that either G is cyclic or for any x in G, x^2=e.
  36. radou

    Cyclic group generator problem

    Homework Statement Let <a> be a cyclic group, where ord(a) = n. Then a^r generates <a> iff r and n are relatively prime. The Attempt at a Solution OK, let n and r be relatively prime. Then ord(a^r) = n. We need to show that for some j, there exists an integer k such that (a^r)^k = a^j...
  37. radou

    Two more simple cyclic group problems

    Homework Statement 1) let <a> be a cyclic group of order n. If n and m are relatively prime, then the function f(x) = x^m is an automorphism of <a>. 2) Let G be a group and a, b be in G. Let a be in <b>. Then <a> = <b> iff a and b have the same order. The Attempt at a Solution 1) It...
  38. radou

    A very simple cyclic group problem

    Homework Statement As the title suggests - this is very simple, I only want to check. Let G be a cyclic group of order n. Then, for every integer k which divides n, there are elements in G of order k. The Attempt at a Solution Now, G = <a>, and a^n = e by definition. Let k be an...
  39. X

    Find the order of the cyclic subgroup of D2n generated by r

    Homework Statement Find the order of the cyclic subgroup of D2n generated by r. Homework Equations The order of an element r is the smallest positive integer n such that r^n = 1. Here is the representation of Dihedral group D2n = <r, s|r^n=s^2=1, rs=s^-1> The elements that are in D2n...
  40. R

    Organic Chemistry: Stabillity of Nitrogen Containing Cyclic Compounds

    Homework Statement Pyridine and pyrrolidine react rapidly with dilute aqueous HCl to form the corresponding hydrochloride salts which are easily purified, isolated and stored in a charge. However, pyrrole, which is another nitrogen-containing heterocycle, does not form a hydrochloride salt...
  41. S

    Reaction Mechanism for 1,3-Dibromopropane to Cyclopropane

    What is the reaction mechanism for 1,3-dibromopropane + 2Na ---> cyclopropane? Thanks :)
  42. B

    How do branes emerge in cyclic universe?

    how do branes emerge in cyclic universe?? ok so in the cyclic model of the universe...two branes are colliding and this is causing big bangs every few trillion years. this solves nicely the initial singularity and explains many things but i have two questions 1) how do these branes...
  43. E

    Isomorphism and Cyclic Groups: Proving Generator Mapping

    Homework Statement I need to prove that any isomorphism between two cyclic groups maps every generator to a generator. 2. The attempt at a solution Here what I have so far: Let G be a cyclic group with x as a generator and let G' be isomorphic to G. There is some isomorphism phi: G...
  44. B

    Cyclic Quadrilaterals: Understanding Angle Equality and Ptolemy's Theorem

    Well this isn't a homework question (I'm just trying to refresh my memory from the plane geometry I did in high school) and so, I was reading through cyclic quadrilaterals on wikipedia and I don't see how certain angles are equal. Here are two images taken from wikipedia...
  45. E

    Cyclic Subgroups of P15: Homework Solutions

    Homework Statement Consider the set P15 of all integer numbers less than 15 that are mutually prime with 15: P15 = {1, 2, 4, 7, 8, 11, 13, 14}. It is a group under multiplication modulo 15. (a) P15 has six cyclic groups. Find them. my answer: <3>=<6>=<9>=<12>= {0, 3, 6 , 9, 12}...
  46. S

    Proving the Existence of Subgroups in Cyclic Groups

    Homework Statement Let G be a finite cyclic group of order n. If d is a positive divisor of n, prove that the equation x^d=e has d distinct solutions Homework Equations n=dk for some k order(G)=nThe Attempt at a Solution solved it: <g^k>={g^k, g^2k,...,g^dk=e} and for all x in <g^k> x^d=e...
  47. D

    Proving G Abelian iff G/Z(G) is Cyclic

    This isn't some homework question its more theory based that I'm struggling with from class and we will probably have homework on it. If G is some arbitrary group, why is G Abelian <---> the factor group of G/Z(G) is cyclic? My professor mentioned something about one direction being trivial...
  48. A

    Thermodynamics: Cyclic Processes

    Thermodynamics: Cyclic Processes (solved) Sorry for the false alarm guys. It looked like I did use the wrong equation while finding the internal energy for case 1. referred to this. Thanks. https://www.physicsforums.com/showthread.php?t=412577 Given that 1 mol of ideal monoatomic gas at p= 1...
  49. bcrowell

    More on Penrose's Conformal Cyclic Cosmology

    We had a discussion of Penrose's conformal cyclic cosmology last month: https://www.physicsforums.com/showthread.php?t=427567 His popular-level book Cycles of Time was published first in the UK, but is now available in the US. I got a copy and have read it, so I can report on a few of the...
  50. M

    Proving Order of Cyclic Group with Elements a & b is Finite

    Homework Statement G is a group. Let a,b be elements of G. If order(ab) is a finite number n, show order(ba) = n as well. Homework Equations order(a) = order(<a>) where <a> is the cyclic group generated by a. The Attempt at a Solution I do not know. I thought it may be related to...
Back
Top