Here the negative binomial distribution has mean parameter and size parameter . Its support in the original PDF is all nonnegative integers; a finite endpoint appearing in the TeX aid would be incorrect. The probability generating function, obtained from the generalized binomial series, is
Differentiating at one gives and . Since the variance is , this proves
The extra positive term explains its overdispersion relative to a Poisson distribution.
For one observation, write the log-likelihood as
The mean score function and its cross derivative are
Taking expectations gives . In addition,
For reference, with the digamma function, the size score function is
Its variance is finite and positive for finite positive . Thus negative binomial mean-size parameter orthogonality makes the expected Fisher information matrix diagonal. For an independent identically distributed sample and a regular identifiable interior true parameter, asymptotic normality of a maximum likelihood estimator gives
Hence the asymptotic correlation is zero. This is first-order asymptotic independence, not a claim of exact finite-sample independence. Indeed the mean score yields at an interior fit, while the size fit also depends on the observed dispersion. The argument excludes a true boundary such as the Poisson limit .
The rational translate has Fourier coefficients , with the same polynomial bound as . Thus the preceding Mellin transform gives, initially for large, the completion of the additive twist of a cusp-form L-function
Write . Nonzero level-one forms have even weight, so . Split the integral at . In its lower part substitute , and use rational-cusp inversion of a level-one cusp form with :
The bounds reverse from to , so
Both cusp values in this integral are as . On any compact set of -values, the remaining powers of are bounded by fixed positive powers of ; differentiation in merely introduces powers of . The integral and its differentiated integrals therefore converge uniformly on compact sets. It defines an entire function of , agreeing with the original completion in its half-plane of convergence, and hence supplies the required analytic continuation to .
For the opposite rational cusp, has inverse modulo . Denote the two individual upper integrals by and . The representation gives
Replacing by in the first equality and using proves the functional equation of an additive cusp-form twist:
For this specializes to the entire completion and functional equation of the ordinary L-function of a cusp form.
Choose , and take the matrix
At its denominator is , while its numerator is . Consequently
Applying the weight- transformation law of the cusp form at proves the rational-cusp inversion of a level-one cusp form:
Use , so . Put . For ,
The Gamma integral and absolute convergence therefore justify exchanging summation and integration. For every positive integer , substitution gives
Summing these identities proves the Mellin transform formula for the Dirichlet series:
The power of the positive real variable uses the real logarithm; the initial half-plane stated above is a sufficient one even when is negative.
The preceding dimension of level-one modular forms gives and . Thus , which begins with , spans . A normalized weight-sixteen Eisenstein series and both have constant term one, so their difference is a multiple of .
There is a normalization error in the printed auxiliary expansion: for the usual normalized , the coefficient multiplier is , rather than . Indeed, the Fourier expansion of a normalized Eisenstein series gives , and the Bernoulli number gives . The printed multiplier is smaller by a factor of . With the correct normalization, the first Fourier coefficients yield
Comparing all positive-index coefficients therefore gives the exact identity
The Fourier coefficients of are integers, as are those of : has its integral divisor-sum expansion and the modular discriminant has the product . Also , and . Reducing the identity modulo and cancelling the invertible multiplier proves the weight-sixteen Eisenstein congruence
The desired congruence is valid; it is the auxiliary normalization in the PDF that requires correction.
A terminal object and pullbacks in a category give a binary product by pulling back . Repeating this gives every finite product, with the empty product supplied by the terminal object. The preceding parts then construct equalizers of arbitrary parallel arrows.
For a diagram with finitely many objects and arrows, form and . Define by and . Their equalizer has projections satisfying every cone equation. Conversely a categorical cone supplies a unique map to , and its cone equations say that this map equalizes , hence factors uniquely through . Thus is the categorical limit. This proves a terminal object and all pullbacks give all finite limits, including the empty diagram.
Define
Every projective point with has a unique unit representative whose third coordinate is positive real, so is a diffeomorphism. More explicitly, in the affine coordinate its inverse is . Lift to the unit sphere by . The last coordinate is real, so its contribution pulls back to zero. The reduction identity therefore yields
This proves the symplectic ball chart in complex projective space directly, including the precise unit radius.
For the final unheaded request, embed the two disjoint balls in this chart. Fix arbitrary , and choose intermediate radii . On the images of the balls of radius , transport the standard complex structure by the given symplectic embeddings. It is compatible with . Their smaller closed neighborhoods are compact and disjoint. Choose a global Riemannian metric agreeing there with the associated compatible metrics, using a partition of unity outside these neighborhoods, and apply the metric construction. The resulting global compatible almost complex structure agrees with the transported standard structure on each ball of radius and on a slightly larger neighborhood. This extends metrics, rather than averaging almost complex structures.
Let be the centres. They are distinct. The degree-one J-holomorphic curve supplied in the question has total area , because its homology class is the projective line class. We use the sharp Euclidean version of the Monotonicity theorem for a J-holomorphic curve: a nonconstant holomorphic curve through the centre of a standard complex ball, with no boundary in the ball and counted with its parametrization multiplicities, has area in the radius- ball at least . This includes branched points: their density is a positive integer , and the stronger lower bound is . One way to see the constant is that complex curves are calibrated minimal surfaces; their stationary area ratio is nondecreasing and its limit at the centre is .
The closed degree-one curve cannot stay entirely inside either chart ball: there the form is exact, so Stokes theorem would give zero total area, contradicting its positive area. Thus the branch through each centre crosses the surrounding spheres, and the stated monotonicity bound applies to each restriction. The two ball images are disjoint, so their area contributions add without overlap. It follows that
Letting both smaller radii increase to their original radii gives
This two-ball packing obstruction in the projective plane is sharper than volume alone: a volume comparison would only give .
Outside both poles, the two geometric series use negative powers:
Hence
The coefficient of vanishes, as it must since the rational function starts with at infinity.
In the middle annulus, expand the pole at one in negative powers and the pole at two in positive powers:
Their geometric series convergence conditions are and , respectively. The required Laurent series is
The coefficient ratio is
Thus the ratio test again gives radius of convergence . On , however, the terms have absolute value , which does not tend to zero. The necessary term condition for a convergent series fails at every boundary point. Therefore this power series diverges everywhere on .
Use dots for derivatives with respect to proper time and the given unit curvature radius. Translation symmetry in the four brane coordinates gives constants
For a future-directed timelike curve . The unit-tangent constraint is
It follows that and . Set . Then
with solution on an interval where the cosine is positive. A phase shift includes either sign of the initial radial velocity. Integrating the four conserved-momentum equations gives the most general trajectory within this patch:
The arbitrary constants encode the initial location and every unit timelike initial velocity. For the past-directed orientation reverse the tangent. The radial turning point is ; the two limits are patch horizons, not the endpoints of the complete globally extended geodesic. This is the timelike geodesics in a warped Poincaré patch solution. As a check, and , which are the explicit geodesic equations.
To measure the acceleration of the surface, take an observer at rest in its flat coordinates: there. The relevant Christoffel coefficient is
Therefore
It points toward decreasing . More generally any observer moving inertially within the brane satisfies , and gives the same normal acceleration. The brane's extrinsic curvature for normal is , consistent with this result. Restoring curvature radius gives warped-brane proper acceleration . Intrinsically the induced brane metric is Minkowski and these observers have zero four-dimensional proper acceleration; the nonzero acceleration is relative to the bulk.
A low-frequency example is Galactic synchrotron emission: relativistic electrons spiral in the Galactic magnetic field and emit a broad nonthermal spectrum. In antenna-temperature units its approximate spectrum is with around3, varying with the electron population and sky direction. It is a major, often dominant contamination at frequencies below roughly20–40GHz; radio point sources and bremsstrahlung can contribute in the same low-frequency region.
A high-frequency example is Galactic thermal dust emission. Grains heated by starlight have approximate modified-blackbody spectrum , with grain temperatures of order tens of kelvin. Their emissivity-weighted emission rises rapidly through the microwave/submillimeter range and commonly dominates anisotropy contamination above roughly100–200GHz, especially at higher frequencies. Dusty extragalactic galaxies provide a related high-frequency foreground.
Synchrotron is the low-frequency contaminant and thermal dust the high-frequency contaminant. There is no universal crossover frequency at which either exceeds CMB anisotropy everywhere: sky masking, angular scale, polarization and source amplitude matter. Cleaner cosmological windows lie between these regimes, and multi-frequency observations distinguish the foreground spectra from a thermodynamic CMB temperature perturbation. The separation into low-frequency emission and high-frequency dust is also used in the Planck astrophysical-component products.
At two derivatives, specify the gauge group and matter representations, a real Kähler potential , a holomorphic superpotential and a symmetric holomorphic gauge kinetic function . Gauge couplings and topological angles are contained in ; global theories can also have allowed Fayet–Iliopoulos terms for Abelian factors. Local theories require the gravitational coupling and consistent gauging: a constant Fayet–Iliopoulos term is not an independent addition to arbitrary supergravity data. A constant in affects supergravity although it is irrelevant in the global theory. is not holomorphic or protected; has no perturbative Wilsonian renormalization; holomorphic is perturbatively one-loop exact. Nonperturbative corrections can modify and , and wave-function renormalization makes physical couplings run despite superpotential non-renormalization. Higher-derivative actions require further data.
Dependence on Grassmann variables alone does not specify a superfield transformation law. A superfield is a function on superspace, with components transforming under the induced supertranslation and Lorentz transformation action. Any suitable superfunction can be an unconstrained superfield once equipped with that action; a fixed element of a Grassmann algebra with independently assigned components need not be covariant. A chiral superfield, for example,
also obeys . Keeping only a nonconstant and forbidding the other components is not a closed supermultiplet: applying a supercharge generates Grassmann-dependent derivative terms. A real unconstrained superfield can instead describe a vector superfield.
Use the standard -oriented partition normalization of B-splines, in contrast to the unit-integral normalization. Thus and on , with equality for a complete basis on its basic knot interval. This terminology does not mean that each basis function's maximum is exactly one; for example an order-three cardinal spline has maximum . Assume the basis has positive support on the integration interval and is continuous, as is needed for a projection taking values in .
Let
The ordinary Gram matrix is positive definite by linear independence. The appropriate row-normalized, or mixed-normalization spline Gram matrix, is
Here is a unit-integral nonnegative spline. Unlike , need not be symmetric. If the full support lies inside the interval, ; otherwise use the actual interval integral rather than that full-support formula.
The normal equations for the orthogonal projection say , with . Divide each row by to obtain
Nonnegativity and unit integral give . The subpartition of unity for B-splines then gives
Taking the supremum over and then over nonzero proves the uniform norm bound for B-spline orthogonal projection:
The row normalization is essential; replacing with the ordinary Gram matrix would not be the same asserted estimate. The operator is defined on and maps into its finite-dimensional spline subspace, onto , not onto all of as one phrase in the PDF says. Its range follows both from the formula and from reproducing every .
If “-normalized” were instead read literally as individually peak-one splines, their sum can exceed one. The basis-dependent factor must then be retained: . Equivalently the displayed bound without an outside factor uses . The standard partition-normalized convention has and yields the sharper bound proved above.
The change of time is , which is positive in the half-plane under consideration. Dividing the two approximate equations by gives
Set . The inhomogeneous system becomes , with eigenvalues . For , write . Integrating with the prescribed initial data gives
and
These expressions also verify both initial values and their initial derivatives. For fixed and small on the outgoing branch, the sine coefficient in is positive and dominates the initial cosine term. The first return to small is near the first positive zero, . Hence
The factor is a half-turn of the growing spiral, not its full rotation period. After this excursion the approximate trajectory approaches the small-, large- region. In the full system the term , omitted during the large excursion, allows the motion to descend along that region and return.
As , the rescaled excursion time diverges and the factor produces arbitrarily large excursions. At the critical value the matrix is a nontrivial Jordan block, and the limiting formula is
For the small outgoing initial data this is positive and unbounded: the unstable manifold no longer turns back. Below the two eigenvalues are real and positive, so there is again no oscillatory return. This quadratic escape desingularization explains loss of the periodic orbit at infinity, together with the unstable-manifold escape, as decreases through . It is not a finite homoclinic bifurcation to the origin. The divergent travel time must not be identified with the physical period without integrating ; the time change becomes singular near .
Here . The origin is a saddle equilibrium, is repelling, and lies in . Thus there is no saddle equilibrium in the interior of to which this periodic orbit could become homoclinic. The origin cannot supply the missing loop: the line is invariant and is precisely its local stable manifold. An orbit in cannot lie on that stable manifold, so the positive periodic orbit cannot close into a homoclinic orbit to the origin either.
The outgoing trajectories do not escape to infinity in this regime. To see the large-amplitude turning mechanism, put once . Direct differentiation gives
Since , the quadratic is uniformly positive. At large while , is bounded below by a positive multiple of , whereas . Thus rises by a fixed amount per bounded increase in : the trajectory reaches and then , where , before can diverge. The same estimate bounds repeated outgoing excursions; large positive also decreases when . Initially negative increases until it becomes nonnegative. These nullcline and ratio estimates give bounded forward excursions.
The repelling upper equilibrium is therefore surrounded by recurrent trajectories, and the Poincaré-Bendixson alternative supplies periodic motion rather than a saddle equilibrium connection. The supercritical attracting periodic orbit persists in the displayed regime, with trajectories spiralling away from the upper equilibrium and approaching it. The last panel of the portrait figure shows this behavior; the boundary stable manifold of the origin is kept separate.

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!
We have two killer features:
  1. 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-calculus
    Articles 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/derivative
  2. 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.
    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.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
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