RUƊIN GANI NA SARARIN SAMANIYA GUDA GOMA SHA ƊAYA SUN SHIGA MAHAWARAR HUBBLE

Tsayayyen Hubble (Hubble constant), H0, yana faɗin saurin faɗaɗar Sararin Samaniya a yau. Ma’auni na baya-bayan nan daga taurarin galaxy na kusa ya ba da kilomita 73.5 a cikin daƙiƙa a kowane megaparsec. Hasashen da aka samo daga hasken bayan fage na microwave (cosmic microwave background), sauran hasken Sararin Samaniya na ƙuruciya, ya ba da 67.4. Biyun sun saɓa da 8 zuwa 9%. Idan wannan saɓanin Hubble (Hubble tension) gaskiya ne, daidaitaccen samfurin ilimin sararin samaniya (cosmology) bai cika ba.

Mafita ita ce ma’auni na uku, mai zaman kansa, mai daidaito sosai har ya zaɓi gefe.

Agogon da aka yi da haske

Idan babban galaxy yana gaban wani quasar mai nisa — tsakiyar wani galaxy mai haske sosai da ke nesa — nauyinsa yana lanƙwasa hasken quasar zuwa hotuna biyu ko huɗu. Hasken suna bin hanyoyi masu tsayi daban-daban, don haka suna isa gare mu a lokuta daban-daban. Quasars suna walƙiya; walƙiya iri ɗaya tana bayyana a kowane hoto bayan wani jinkirin lokaci.

Waɗannan jinkiri, tare da samfurin nauyin galaxy mai lanƙwasawa, suna ba da cikakken nisa kuma, daga gare shi, H0. Hanyar ba ta buƙatar tsani na nisan tsakiya kuma ƙura kusan ba ta shafar ta.

Rikitarwar da ke ɓoye a cikin nauyi

Akwai matsala. Siffofin nauyi daban-daban da yawa za su iya samar da hotuna iri ɗaya daidai yayin da suke canza jinkirin — don haka kuma H0. Masana taurari suna kiran ta rikitarwar shimfiɗar nauyi (mass-sheet degeneracy). Ma’aunai na baya sun kai 2% ta hanyar ɗaukar siffa mai sauƙi. Da aka watsar da wannan zato a 2020, rashin tabbas ya yi tsalle zuwa 8%.

Hanya ɗaya tilo ta tantance nauyin ba tare da ɗaukar siffarsa ba ita ce auna saurin motsin taurari a cikin galaxy mai lanƙwasawa. Abin da ƙungiyar TDCOSMO, masu bincike 28 a ƙasashe goma, ke yi kenan.

Abin da ya canza cikin shekara guda

Idan aka kwatanta da sakamakonsu na 2025, suna da:

• quasar 11 da aka lanƙwasa maimakon 8 (tara masu hotuna huɗu, biyu masu hotuna biyu);
• taswirorin motsin taurari da aka warware a cikin galaxy ga 9 daga cikinsu, shida da aka yi da spectrograph NIRSpec na Na’urar Hangen Nesa ta Sararin Samaniya ta James Webb;
• hotunan Webb mafi kaifi ga masu lanƙwasawa uku;
• cikakkun samfuran girma biyu na motsin taurarin galaxies, maimakon ƙiyasin siffar ƙwallo;
• sabbin ƙiyasin abubuwan da ke kan kowace hanyar gani, bisa kwaikwayon da aka shirya don aikin Euclid.

An yi binciken a makance: an ɓoye ƙimomin ilimin sararin samaniya har sai an kammala bita ta cikin gida. An bayyana sakamakon a ranar 23 ga Satumba 2026 kuma an buga shi ba tare da canji ba.

71.1, a 3.3%

Idan aka haɗa da samfurin supernova da ke tantance yawan abu a Sararin Samaniya, masu lanƙwasawa goma sha ɗaya sun ba da:

• H0 = 71.1 km/s/Mpc, rashin tabbas 3.3% — ya fi na 2025 matsewa da 35%;
• 71.3 a 3.0% idan aka ƙara wasu galaxies masu lanƙwasawa 23 marasa jinkirin lokaci;
• 72.2 a 3.0% idan aka musanya supernovae da ma’aunin nisa na binciken galaxy na DESI.

Da masu lanƙwasawa kaɗai ba tare da bayanai na waje ba, ƙimar ita ce 70.6 a 4.9%. Canza zaɓuɓɓukan bincike ɗaya bayan ɗaya yana matsar da H0 ƙasa da karkacewar ma’auni (standard deviation) ɗaya. A cewar marubutan, tsanin nisa na kusa ne kaɗai ya fi daidaito a cikin hanyoyin auna Sararin Samaniya na baya-bayan nan.

Wane gefe?

Sakamakon yana cikin karkacewar ma’auni ɗaya na ma’aunin taurarin galaxy na kusa kuma sigma 1.6 sama da hasashen farkon Sararin Samaniya — sigma 2.2 a haɗin da ya fi daidaito. Wata takarda abokiya, wadda ba a tattauna a nan ba, ta haɗa shi da wasu hanyoyin auna Sararin Samaniya na baya-bayan nan kuma ta ba da rahoton saɓani da hasken bayan fage na microwave na kusan sigma 2.7 ko fiye.

Masu lanƙwasawa har za su iya daidaita ma’aunin sararin samaniya na binciken DESI ba tare da hasken bayan fage na microwave ba. Sun ba da iyakar sauti (sound horizon) na 140.7 ± 4.3 megaparsec, kusan sigma 1.5 ƙasa da ƙimar da aka samo daga tauraron ɗan adam na Planck.

Ɗan turawa kan makamashi mai duhu

Da aka maimaita binciken tare da barin makamashi mai duhu ya canza, H0 kusan ba ya motsawa. Idan aka haɗa da DESI da supernovae, bayanan suna ɗan nuna rashin goyon baya ga makamashi mai duhu da ke zama tsayayye cikakke, da sigma 2.3 zuwa 2.5 — abin lura, amma nesa da gano wani abu. Auna makamashi mai duhu yadda ya kamata da wannan hanya zai buƙaci masu lanƙwasawa da yawa fiye da haka, waɗanda ake sa ran za su fito daga Euclid, Rubin Observatory da na’urar hangen nesa ta Roman.

Marubutan sun lura cewa sabuwar ƙimar ta dace da dukan ma’aunansu na makance na baya, duk da sabbin bayanai, sabbin hanyoyi da sababbin mutane. An gabatar da takardar ga Physical Review D; za a saki bayanan da zarar an karɓe ta.