An artist is a person engaged in one or more of any of a broad spectrum of activities related to creating art, practicing the arts and / or demonstrating an art.

Black is the color of objects that do not emit or reflect light in any part of the visible spectrum ; they absorb all such frequencies of light.

The spectrum of any element x is a closed subset of the closed disc in C with radius || x || and center 0, and thus is compact.

* The spectrum of any bounded linear operator on a Banach space is a nonempty compact subset of the complex numbers C. Conversely, any compact subset of C arises in this manner, as the spectrum of some bounded linear operator.

For instance, a diagonal operator on the Hilbert space may have any compact nonempty subset of C as spectrum.

Spectroscopic studies revealed absorption lines in the Jovian spectrum due to diatomic sulfur ( S < sub > 2 </ sub >) and carbon disulfide ( CS < sub > 2 </ sub >), the first detection of either in Jupiter, and only the second detection of S < sub > 2 </ sub > in any astronomical object.

These are capable of the most severe types of molecular damage, which can happen in biology to any type of biomolecule, including mutation and cancer, and often at great depths from the skin, since the higher end of the X-ray spectrum, and all of the gamma ray spectrum, are penetrating to matter.

Fascists have commonly opposed having a firm association with any section of the left-right spectrum, considering it inadequate to describe their beliefs, though fascism's goal to promote the rule of people deemed innately superior while seeking to purge society of people deemed innately inferior is identified as a prominent far-right theme.

Individuals were categorized according to their so-called " rejection spectrum " which allowed doctors to counter any immune system responses to the new organs, allowing transplants to " take " for life.

We can also show that the possible values of the observable A in any state must belong to the spectrum of A.

In linguistics the term orthography is often used to refer to any method of writing a language, without judgment as to right and wrong, with a scientific understanding that orthographic standardization exists on a spectrum of strength of convention.

Pacifism covers a spectrum of views ranging from the belief that international disputes can and should be peacefully resolved ; to calls for the abolition of the institutions of the military and war ; to opposition to any organization of society through governmental force ( anarchist or libertarian pacifism ); to rejection of the use of physical violence to obtain political, economic or social goals ; to opposition to violence under any circumstance, including defense of self and others.

Pacifism covers a spectrum of views, including the belief that international disputes can and should be peacefully resolved, calls for the abolition of the institutions of the military and war, opposition to any organization of society through governmental force ( anarchist or libertarian pacifism ), rejection of the use of physical violence to obtain political, economic or social goals, the obliteration of force except in cases where it is absolutely necessary to advance the cause of peace, and opposition to violence under any circumstance, even defense of self and others.

If the surface has any transparent or translucent properties, it refracts a portion of the light beam into itself in a different direction while absorbing some ( or all ) of the spectrum ( and possibly altering the color ).

Fundamental strings exist in 9 dimensions and the strings can vibrate in any direction, meaning that the spectrum of vibrational modes is much richer.

As with any religious movement, a theological spectrum exists within Adventism comparable to the fundamentalist-moderate-liberal spectrum in the wider Christian church and in other religions.

In general, any particular instrument will operate over a small portion of this total range because of the different techniques used to measure different portions of the spectrum.

In abstract algebra and algebraic geometry, the spectrum of a commutative ring R, denoted by Spec ( R ), is the set of all proper prime ideals of R. It is commonly augmented with the Zariski topology and with a structure sheaf, turning it into a locally ringed space.

As a rule of thumb, any sort of construction that takes as input a fairly general object ( often of an algebraic, or topological-algebraic nature ) and outputs a compact space is likely to use Tychonoff: e. g., the Gelfand space of maximal ideals of a commutative C * algebra, the Stone space of maximal ideals of a Boolean algebra, and the Berkovich spectrum of a commutative Banach ring.

If X is an algebraic variety carrying the Zariski topology, we can define a locally ringed space by taking O < sub > X </ sub >( U ) to be the ring of rational functions defined on the Zariski-open set U which do not blow up ( become infinite ) within U. The important generalization of this example is that of the spectrum of any commutative ring ; these spectra are also locally ringed spaces.

Let P be a finitely generated projective module over a commutative ring R and X be the spectrum of R. The rank of P at a prime ideal in X is the rank of the free-module.

He defined the spectrum of a commutative ring as the space of prime ideals with Zariski topology, but augments it with a sheaf of rings: to every Zariski-open set he assigns a commutative ring, thought of as the ring of " polynomial functions " defined on that set.

An affine scheme is a locally ringed space isomorphic to the spectrum of a commutative ring.

We denote the spectrum of a commutative ring A by Spec ( A ).

The functor associates to every commutative ring its spectrum, the scheme defined by the prime ideals of the ring.

* Affine scheme, the spectrum of prime ideals of a commutative ring

Zero divisors have a topological interpretation, at least in the case of commutative rings: a ring R is an integral domain, if and only if it is reduced and its spectrum Spec R is an irreducible topological space.

Any affine group scheme is the spectrum of a commutative Hopf algebra ( over a base S, this is given by the relative spectrum of an O < sub > S </ sub >- algebra ).

For an arbitrary group scheme G, the ring of global sections also has a commutative Hopf algebra structure, and by taking its spectrum, one obtains the maximal affine quotient group.

In mathematics, a spectral space is a topological space which is homeomorphic to the spectrum of a commutative ring.

# X is homeomorphic to the spectrum of a commutative ring.

The prime spectrum Spec ( R ) of a commutative ring R with the Zariski topology is a compact sober T < sub > 0 </ sub > space.

For example, there is a duality between commutative rings and affine schemes: to every commutative ring A there is an affine spectrum, Spec A, conversely, given an affine scheme S, one gets back a ring by taking global sections of the structure sheaf O < sub > S </ sub >.

In functional analysis, a branch of mathematics, the Borel functional calculus is a functional calculus ( that is, an assignment of operators from commutative algebras to functions defined on their spectrum ), which has particularly broad scope.

* In commutative algebra, a commutative ring R is irreducible if its prime spectrum, that is, the topological space Spec R, is an irreducible topological space.

A complex orientation on an associative commutative ring spectrum E is an element x in E < sup > 2 </ sup >( CP < sup >∞</ sup >) whose restriction to E < sup > 2 </ sup >( CP < sup > 1 </ sup >)

* the Zariski topology on an algebraic variety or on the spectrum of a ring, used in algebraic geometry,

Prime ideals are the points of algebro-geometric objects, via the notion of the spectrum of a ring.

It follows readily from the definition of the spectrum of a ring, the space of prime ideals of equipped with the Zariski topology, that the Krull dimension of is precisely equal to the irreducible dimension of its spectrum.

* In the category of schemes, Spec ( Z ) the prime spectrum of the ring of integers is a terminal object.

The empty scheme ( equal to the prime spectrum of the trivial ring ) is an initial object.

Modern algebraic geometry takes the spectrum of a ring ( the set of proper prime ideals ) as its starting point.

Thus, V ( S ) is " the same as " the maximal ideals containing S. Grothendieck's innovation in defining Spec was to replace maximal ideals with all prime ideals ; in this formulation it is natural to simply generalize this observation to the definition of a closed set in the spectrum of a ring.

* Spec k, the spectrum of the polynomial ring over a field k, which is also denoted, the affine line: the polynomial ring is known to be a principal ideal domain and the irreducible polynomials are the prime elements of k. If k is algebraically closed, for example the field of complex numbers, a non-constant polynomial is irreducible if and only if it is linear, of the form t − a, for some element a of k. So, the spectrum consists of one closed point for every element a of k and a generic point, corresponding to the zero ideal.

Just as in classical algebraic geometry, any spectrum or projective spectrum is compact, and if the ring in question is Noetherian then the space is a Noetherian space.

In the NMR spectrum of a dimethyl derivative, two nonequivalent signals are found for the two methyl groups indicating that the molecular conformation of this cation not perpendicular ( as in A ) but is bisected ( as in B ) with the empty p-orbital and the cyclopropyl ring system in the same plane:

A scheme is a locally ringed space such that every point has a neighbourhood, which, as a locally ringed space, is isomorphic to a spectrum of a ring.

If the same signal is sent to both inputs of a ring modulator, the resultant harmonic spectrum is the original frequency domain doubled ( if f < sub > 1 </ sub >

An equivalent but streamlined construction is given by the Proj construction, which is an analog of the spectrum of a ring, denoted " Spec ", which defines an affine scheme.

* Formal spectrum of a ring, a construction in algebraic geometry