ترغب بنشر مسار تعليمي؟ اضغط هنا

On the Instability and Critical Damping Conditions, $ktau = 1/e$ and $ktau = pi/2$ of the equation $dot{theta} = -k theta(t-tau)$

244   0   0.0 ( 0 )
 نشر من قبل Z. Jane Wang
 تاريخ النشر 2014
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Z. Jane Wang




اسأل ChatGPT حول البحث

In this note, I show that it is possible to use elementary mathematics, instead of the machinery of Lambert function, Laplace Transform, or numerics, to derive the instability condition, $k tau = pi/2$, and the critical damping condition, $ktau = 1/e$, for the time-delayed equation $dot{theta} = -k theta(t-tau)$. I hope it will be useful for the new comers to this equation, and perhaps even to the experts if this is a simpler method compared to othe

قيم البحث

اقرأ أيضاً

We extend a recent computation of the dependence of the free energy, F, on the noncommutative scale $theta$ to theories with very different UV sensitivity. The temperature dependence of $F$ strongly suggests that a reduced number of degrees of freedo m contributes to the free energy in the non-planar sector, $F_{rm np}$, at high temperature. This phenomenon seems generic, independent of the UV sensitivity, and can be traced to modes whose thermal wavelengths become smaller than the noncommutativity scale. The temperature dependence of $F_{rm np}$ can then be calculated at high temperature using classical statistical mechanics, without encountering a UV catastrophe even in large number of dimensions. This result is a telltale sign of the low number of degrees of freedom contributing to $F$ in the non-planar sector at high temperature. Such behavior is in marked contrast to what would happen in a field theory with a random set of higher derivative interactions.
244 - J.J. Dudek , F.E. Close 2003
If the exotic baryon $Theta(1540)$ is $ududbar{s}$ with $J^P = {1/2}^+$, we predict that there is a 10bar with $J^P = {3/2}^+$ containing a $Theta^*(1540-1680)$. The width $Gamma(Theta^* to KN)$ is at least a factor of three larger than $Gamma(Thet a)$. The possibilities of $Theta^* to KNpi$ or $Theta gamma$ via $M1$ and $E2$ multipoles are discussed.
In this paper we improve the understanding of the cofactor conditions, which are particular conditions of geometric compatibility between austenite and martensite, that are believed to influence reversibility of martensitic transformations. We also i ntroduce a physically motivated metric to measure how closely a material satisfies the cofactor conditions, as the two currently used in the literature can give contradictory results. We introduce a new condition of super-compatibility between martensitic laminates, which potentially reduces hysteresis and enhances reversibility. Finally, we show that this new condition of super-compatibility is very closely satisfied by Zn45Au30Cu25, the first of a class of recently discovered materials, fabricated to closely satisfy the cofactor conditions, and undergoing ultra-reversible martensitic transformation.
We study 2d U(1) gauge Higgs systems with a $theta$-term. For properly discretizing the topological charge as an integer we introduce a mixed group- and algebra-valued discretization (MGA scheme) for the gauge fields, such that the charge conjugation symmetry at $theta = pi$ is implemented exactly. The complex action problem from the $theta$-term is overcome by exactly mapping the partition sum to a worldline/worldsheet representation. Using Monte Carlo simulation of the worldline/worldsheet representation we study the system at $theta = pi$ and show that as a function of the mass parameter the system undergoes a phase transition. Determining the critical exponents from a finite size scaling analysis we show that the transition is in the 2d Ising universality class. We furthermore study the U(1) gauge Higgs systems at $theta = pi$ also with charge 2 matter fields, where an additional $Z_2$ symmetry is expected to alter the phase structure. Our results indicate that for charge 2 a true phase transition is absent and only a rapid crossover separates the large and small mass regions.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا