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At fluid Toomre parameter , the local spiral-wave dispersion relation becomes . The minus-sign, longer-wavelength root is nonnegative only between the two Lindblad resonance conditions. The plus-sign, shorter-wavelength root remains positive outside that interval. Thus this dispersion relation alone does not prove that every density wave is confined between Lindblad resonances; an additional physical restriction is needed.
For constant circular speed , angular velocity is and radial epicyclic frequency is . Constant effective random speed and surface density then give . The local axisymmetric fluid model is stable inside and unstable outside it. This statement is conditional on the thin-disk local approximation, rather than a proof of global or collisionless stability.
Changing the trap frequency changes the equilibrium spacing proportionally to without shifting the centre. The old equilibrium displacement from the new one is parallel to the breathing eigenvector. Starting at rest therefore excites that mode alone at linear order; the outer charges oscillate equally and oppositely while the central charge stays fixed.
Two narrow incoherent lines of powers and wave-number difference give visibility in a Michelson scan of one-way arm difference . The minimum is , and revivals repeat in . Finite linewidth damps this envelope.
A microstructure in which carbon redistribution and carbide formation reduce the supersaturation of a martensitic matrix. Plate or lath morphology can remain while local strain and thermodynamic phase composition evolve. The term describes a material state, not a universal guarantee of a particular toughness.
Latent heat of a temperature-dependent cubic-quartic Landau transition by
Codex 0 Created 2026-10-20 Updated 2026-11-05
At an equilibrium minimum, because . For , the entropy decrease at coexistence is . Multiplying by gives the positive latent heat released on cooling. The units are total heat or heat density according to the normalization of .
When in the stated model, the broken, nonzero minimum remains globally preferred at every finite temperature. A metastable zero state can still exist for , but its lifetime and a nucleation temperature are kinetic questions. Its disappearance at the spinodal point is not an equilibrium coexistence temperature.
The 15 Cartesian displacements of tetrahedral methane have characters on classes . Removing translations and rotations gives and the stated decomposition. There are nine vibrational coordinates in four frequency families.
The Taylor remainder in this form evaluates one higher derivative at an intermediate point between the expansion point and . If on that interval, then . This bounds truncation error without knowing the particular intermediate point. The differentiability hypotheses are those of the Taylor theorem with Lagrange remainder.
For a nonzero real constant , the tangent line to at passes through the origin precisely when . Thus , , and its slope is . This gives the unique such tangent line. If , the graph is the horizontal line and no tangent line through the origin exists. The equality between the derivative and the slope from the origin, , is useful for other differentiable functions too.
A line tangent to two curves or to a curve at two distinct points. For functions , contact at requires equal derivatives and equal intercepts: and . The common-tangent construction uses the lower supporting line for phase coexistence.
The identical two-atom motif adds a factor to the FCC lattice structure factor. Among even-index FCC diffraction reflections, only those with divisible by4 survive. The allowed FCC reflection200 therefore vanishes for equal motif scattering amplitudes.
The displayed conjugacy classes have sizes one, one, two, two and two. The identity and half-turn are central elements. Reflection sends to , pairing the two quarter-turns. Conjugating a reflection by sends to ; conjugating by sends it to . Thus the parity of is invariant under conjugation, separating the axis reflections from the diagonal reflections, and each displayed pair is one conjugacy class.
In the order of the conjugacy classes of the symmetry group of a square displayed there, its irreducible complex character table isThe four one-dimensional representations assign independent signs to and . The remaining row is the character of the ordinary planar representation: a rotation has trace and a reflection has trace zero. Weighted by class sizes, these rows satisfy character orthogonality. Their squared dimensions sum to eight, so they exhaust the irreducible representations.
Enhancement of molecular excitation and Raman emission by the local optical response of a nanostructure. Pump and emitted frequencies both enter the enhancement factor.
A change in Raman response from adsorption-induced electronic coupling or charge-transfer resonance, distinct from enhancement of the external optical field alone.
A self-similar energy-conserving strong spherical explosion into a uniform ambient density has and . The dimensionless coefficient depends on the equation of state. Radiative losses, nonuniform media or continuous energy injection alter the similarity solution.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.Figure 3. Visual Studio Code extension installation.Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. - Infinitely deep tables of contents:
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