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===Multipoli bassi ed altre anomalie===
WithCon thei increasinglydati precisesempre datapiù providedprecisi byforniti dal WMAP, thereci havesono beenstate auna numberserie ofdi claimssegnalazioni thatsecondo thecui la CMB sufferssoffre fromdi anomaliesanomalie, suchcome asanisotropie verysu great-scalegrandissima anisotropiesscala, anomalousallineamenti alignmentsanomali, ande distribuzioni non-Gaussian distributions.gaussiane<ref name="arXiv:0905.2854v2">{{cite arxiv|last=Rossmanith|first=G.|coauthors=' Rossmanith et al., 2009, ''|year=2009|title=Non-Gaussian Signatures in the five-year WMAP data as identified with isotropic scaling indices'' {{arxiv|class=astro-ph.CO|eprint=0905.2854}}</ref><ref name="arXiv:0802.3229">{{cite arxiv|last=Schild|first=R. E.|last2=Gibson|first2= Schild, C. H.|year= Gibson, 2008|title=, ''Goodness in the Axis of Evil'' {{arxiv|class=astro-ph|eprint=0802.3229}}</ref><ref name="arXiv:astro-ph/0511666">{{citeA. arxiv|last=Bernui|first=A.|coauthors='' et al., 2005, ''|year=2005|title=Mapping the large-scale anisotropy in the WMAP data'' {{arxiv|class=astro-ph|eprint=astro-ph/0511666}}</ref><ref name="arXiv:astro-ph/0503213">{{cite arxiv|last=Jaffe|first=T. R.|coauthors='' Jaffe et al., 2005, ''|year=2005|title=Evidence of vorticity and shear at large angular scales in the WMAP data: a violation of cosmological isotropy?''{{arxiv|class=astro-ph|eprint=astro-ph/0503213}}</ref> The most longstanding of these is the low-''l'' multipole controversy. Even in the COBE map, it was observed that the [[quadrupole]] (''l''=2 spherical harmonic) has a low amplitude compared to the predictions of the big bang. Some observers have pointed out that the anisotropies in the WMAP data did not appear to be consistent with the big bang picture. In particular, the quadrupole and octupole (''l''=3) modes appear to have an unexplained alignment with each other and with the [[plane of the ecliptic|ecliptic plane]]<ref>
La più duratura di queste è la polemica ''low-l'' multipolare. Anche nella mappa del COBE si è osservato che il [[Momento di quadrupolo elettrico
|quadrupolo]] (''l'' = 2 [[armonica sferica|armoniche sferiche]]) ha una ampiezza bassa rispetto alle previsioni del Big Bang. Alcuni osservatori hanno fatto notare che le anisotropie nei dati del WMAP non sembrano essere coerenti con il quadro del big bang. In particolare, il quadrupolo e l'octupolo (''l'' = 3) sembrano avere un allineamento inspiegabile l'uno con l'altro e con il piano dell'eclittica<ref>
{{cite journal|last=de Oliveira-Costa |first=A. |coauthors=''et al.''|year=2004|title=The significance of the largest scale CMB fluctuations in WMAP|journal=[[Physical Review D]]|volume=69|pages=063516|doi=10.1103/PhysRevD.69.063516|id={{arxiv|astro-ph/0307282}}}}</ref><ref>{{cite journal|last=Schwarz|first=D. J.|coauthors=''et al,''|year=2004|title=Is the low-''l'' microwave background cosmic?|journal=[[Physical Review Letters]]|volume=93|pages=221301|doi=10.1103/PhysRevLett.93.221301|id={{arxiv|astro-ph/0403353}}}}</ref><ref>
{{cite journal|last=Bielewicz|first=P.|last2=Gorski|first2=K. M.|last3=Banday|first3=A. J.|year=2004|title=Low-order multipole maps of CMB anisotropy derived from WMAP|journal=[[Monthly Notices of the Royal Astronomical Society]]|volume=355|pages=1283|doi=10.1111/j.1365-2966.2004.08405.x|id={{arxiv|astro-ph/0405007}}}}</ref>, anun alignmentallineamento sometimesa referredvolte toindicato ascome the''l'asse del male''<ref>In originale, ''axis of evil''.</ref><ref name="arXiv:0802.3229"/>. Un certo Anumero numberdi ofgruppi groupshanno havesuggerito suggestedche thatquesto thispotrebbe couldessere bela thefirma signaturedi ofuna newnuova physicsfisica atalle thescale greatestpiù observablegrandi scalesosservabili. UltimatelyIn ultima analisi, duea tocausa thedei foregroundsprimi andpiani thee [[cosmicdel variance]]problema problemdella varianza cosmica, thele greatestmodalità modespiù willgrandi nevernon besaranno asmai wellmisurabili measuredcome asle themodalità smalla angularpiccola scalescala modesangolare. TheLe analysesanalisi weresono performedstate oneffettuate twosu mapsdue thatmappe havealle hadquali thesono foregroundsstati removedrimossi asi bestprimi aspiani isnel possiblemiglior modo possibile: thela "internalmappa lineardella combination"combinazione maplineare ofinterna" thedel WMAP collaboratione anduna amappa similarsimile mappreparata prepared byda [[Max Tegmark]] ande others.altri<ref name="hinshaw07">{{cite journal|last=Hinshaw|first=G.|coauthors=''et al.'' (WMAP collaboration)|year=2007|title=Three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: temperature analysis|journal=[[Astrophysical Journal]] (Supplement Series)|volume=170|issue=2|pages=288–334|doi=10.1086/513698|id={{arxiv|astro-ph/0603451}}}}</ref><ref name="FirstWMAP">
{{cite journal|last=Bennett|first=C. L.|coauthors=''et al.'' (WMAP collaboration)|year=2003|title=First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: preliminary maps and basic results|journal=[[Astrophysical Journal]] (Supplement Series)|volume=148|pages=1|doi=10.1086/377253|id={{arxiv|astro-ph/0302207}}}} This paper warns, "the statistics of this internal linear combination map are complex and inappropriate for most CMB analyses."</ref><ref>
{{cite journal|last=Tegmark|first=M.|last2=de Oliveira-Costa|first2=A.|last3=Hamilton|first3=A.|year=2003|title=A high resolution foreground cleaned CMB map from WMAP|journal=[[Physical Review D]]|volume=68|pages=123523|id={{arxiv|astro-ph/0302496}}|doi=10.1103/PhysRevD.68.123523}} This paper states, "Not surprisingly, the two most contaminated multipoles are [the quadrupole and octopole], which most closely trace the galactic plane morphology."</ref>. LaterAnalisi analysessuccessive havehanno pointedevidenziato outche thatqueste thesesono arele themodalità modespiù mostsensibili susceptiblealla tocontaminazione foregrounddel contaminationprimo frompiano [[synchrotronda radiation#Synchrotron radiation in astronomy|synchrotron]]sincrotrone, dustpolvere, and [[Bremsstrahlung|free-freebremsstrahlung]] emission, ande fromda experimentalincertezze uncertaintysperimentali innel themonopolio monopolee andnel dipoledipolo. A full Un'[[BayesianInferenza analysisbayesiana|analisi bayesiana]] ofdello thespettro di potenza del WMAP powerdimostra spectrumche demonstratesla thatprevisione thedel quadrupolequadrupolo predictiondella ofcosmologia [[modello Lambda-CDM model|Lambda-CDM cosmology]] isè consistentcoerente withcon thei datadati atal thelivello del 10% levele andche thatl'octupolo theosservato observednon octupoleè is not remarkable.notevole<ref>{{cite journal|last=O'Dwyer|first=I.|coauthors=''et al.''|year=2004|title=Bayesian Power Spectrum Analysis of the First-Year Wilkinson Microwave Anisotropy Probe Data|journal=[[Astrophysical Journal Letters]]|volume=617|pages=L99–L102|doi=10.1086/427386|id={{arxiv|astro-ph/0407027}}}}</ref>. CarefullyConti accountingpiù forattenti thesulla procedureprocedura usedutilizzata toper removerimuovere theil foregroundsprimo frompiano thedalla fullmappa skydel mapcielo furtherpieno reducesriduce theulteriormente significancel'importanza ofdell'allineamento thedel alignment by ~5%. circa<ref>
{{cite journal|last=Slosar|first=A.|last2=Seljak|first2=U.|year=2004|title=Assessing the effects of foregrounds and sky removal in WMAP|journal=[[Physical Review D]]|volume=70|pages=083002|doi=10.1103/PhysRevD.70.083002|id={{arxiv|astro-ph/0404567}}}}</ref><ref>{{cite journal|last=Bielewicz|first=P.|coauthors=''et al.''|year=2005|title=Multipole vector anomalies in the first-year WMAP data: a cut-sky analysis|journal=[[Astrophysical Journal]]|volume=635|pages=750–60|doi=10.1086/497263|id={{arxiv|astro-ph/0507186}}}}</ref><ref>{{cite journal|last=Copi |first=C.J. |coauthors=''et al.''|year=2006|title=On the large-angle anomalies of the microwave sky|journal=[[Monthly Notices of the Royal Astronomical Society]]|volume=367|pages=79–102|doi=10.1111/j.1365-2966.2005.09980.x|id={{arxiv|astro-ph/0508047}}}}</ref><ref>
{{cite journal|last=de Oliveira-Costa|first=A.last2=Tegmark|first2=M.|year=2006|title=CMB multipole measurements in the presence of foregrounds|journal=[[Physical Review D]]|volume=74|pages=023005|doi=10.1103/PhysRevD.74.023005|id={{arxiv|astro-ph/0603369}}|last2=Tegmark}}</ref>.
==Notes==
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